DI37Q–03
Vehicle Brought to Workshop
Customer Problem Analysis P. DI–2
Problem Symptom ConfirmationIf engine does not start perform steps 10 and 12 first
Connect OBD II scan tool or TOYOTA hand–held tester to DLC3 P. DI–3If display indicates a communication fault in tool, inspect DLC3 P. DI–3
Check DTC and Freezed Frame Data (Pre–check)
Record or Print DTC and Freezed Frame Data P. DI–3
Clear DTC and Freezed Frame Data P. DI–3
Visual Inspection
Setting Check Mode Diagnosis P. DI–3
Symptom Simulation P. IN–18
Basic Inspection P. DI–3 DTC Chart P. DI–14
Problem Symptoms Table P. DI–21
Circuit Inspection P. DI–23
Adjustment, Repair
DTC Check P. DI–3
Titles inside are titles of pages in
in the bottom portion. See the indicatedpages for detailed explanations.
this manual with the page number indicated
Malfunctionoccurs.
Malfunction does not occur.
Parts Inspection
Check for Intermittent Problems P. DI–3
Identification of Problem
Confirmation Test
End
1
2
3
4
5
6
7
10
8
9
11
12
13
15
14
16
Normal Malfunction code.
17
–DIAGNOSTICS ENGINEDI–1
165Author: Date:
2000 MR2 (RM760U)
ENGINEHOW TO PROCEED WITH TROUBLESHOOTINGTroubleshoot in accordance with the procedure on the following pages.
DI37R–03
ENGINE CONTROL SYSTEM Check Sheet
Customer’s Name
Driver’s Name
Data VehicleBrought in
License No.
Model and ModelYear
Frame No.
Engine Model
Odometer Reading
Pro
blem
Sym
ptom
s
Engine doesnot Start
Difficult toStart
Poor Idling
PoorDrivability
Engine Stall
Others
Engine does not crank No initial combustion No complete combustion
Engine cranks slowlyOther
Incorrect first idle Idling rpm is abnormal High ( rpm) Low ( rpm)Rough idling Other
Hesitation Back fire Muffler explosion (after–fire) SurgingKnocking Other
Soon after starting After accelerator pedal depressedAfter accelerator pedal released During A/C operationShifting from N to D Other
Data ProblemOccurred
Problem Frequency
Con
ditio
n W
hen
Pro
blem
Occ
urs
Weather
Engine Operation
Engine Temperature
Place
OutdoorTemperature
Constant Sometimes ( times per day/month) Once onlyOther
Fine Cloudy Rainy Snowy Various/Other
Hot Warm Cool Cold (approx. °F/ °C)
Highway Suburbs Inner city Uphill DownhillRough road Other
Cold Warming up After warming up Any temperature Other
Starting Just after starting ( min.) Idling RacingDriving Constant speed Acceleration DecelerationA/C switch ON/OFF Other
Condition of MIL Remains on Sometimes lights up Does not light up
Normal Malfunction code(s) (code )Freezed frame data ( )
Normal Malfunction code(s) (code )Freezed frame data ( )
Normal Mode(Pre–check)
Check Mode
DTC Inspection
Inspector’sName
kmmiles
DI–2–DIAGNOSTICS ENGINE
166Author: Date:
2000 MR2 (RM760U)
CUSTOMER PROBLEM ANALYSIS CHECK
A13068
DI37S–04
A12801
TOYOTA Hand–held Tester
DLC3
–DIAGNOSTICS ENGINEDI–3
167Author: Date:
2000 MR2 (RM760U)
PRE–CHECK1. DIAGNOSIS SYSTEM(a) Description
When troubleshooting OBD II vehicles, the only dif-ference from the usual troubleshooting procedureis that you need to connect the vehicle to the OBDII scan tool complying with SAE J1978 or TOYOTAhand–held tester, and read off various data outputfrom the vehicle’s ECM.
OBD II regulations require that the vehicle’s on–board computer lights up the Malfunction IndicatorLamp (MIL) on the instrument panel when the com-puter detects a malfunction in the emission controlsystem/components or in the powertrain controlcomponents which affect vehicle emissions, or amalfunction in the computer. In addition to the MILlighting up when a malfunction is detected, the ap-plicable Diagnostic Trouble Code (DTC) prescribedby SAE J2012 are recorded in the ECM memory(See page DI–14).
If the malfunction does not reoccur 3 trips, the MIL goes off au-tomatically but the DTCs remain recorded in the ECM memory.
To check the DTCs, connect the OBD II scan tool orTOYOTA hand–held tester to the Data Link Con-nector 3 (DLC3) on the vehicle. The OBD II scantool or TOYOTA hand–held tester also enables youto erase the DTCs and check freezed frame dataand various forms of engine data (For operatinginstructions, see the OBD II scan tool’s instructionbook.).DTCs include SAE controlled codes and manufac-turer controlled codes. SAE controlled codes mustbe set as prescribed by the SAE, while manufactur-er controlled codes can be set freely by themanufacturer within the prescribed limits (See DTCchart on page DI–14).
DI–4–DIAGNOSTICS ENGINE
168Author: Date:
2000 MR2 (RM760U)
The diagnosis system operates in the normal modeduring normal vehicle use. It also has a check modefor technicians to simulate malfunction symptomsand troubleshoot. Most DTCs use 2 trip detectionlogic* to prevent erroneous detection, and ensurethorough malfunction detection. By switching theECM to the check mode when troubleshooting, thetechnician can cause the MIL to light up for a mal-function that is only detected once or momentarily(TOYOTA hand–held tester only)(See page DI–3).
*2 trip detection logic: When a malfunction is first detected, the malfunc-tion is temporarily stored in the ECM memory (1sttrip).
If the same malfunction is detected again during the seconddrive test, this second detection causes the MIL to light up (2ndtrip). (However, the ignition switch must be turned OFF betweenthe 1st trip and 2nd trip.)
Freeze frame data:Freeze frame data records the engine conditionwhen a misfire (DTC P0300 – P0304) or fuel trimmalfunction (DTC P0171, P0172, P0174 andP0175) or other malfunction (first malfunction only),is detected.Because freeze frame data records the engineconditions (fuel system, calculated load, enginecoolant temperature, fuel trim, engine speed, ve-hicle speed, etc.) when the malfunction is detected.When troubleshooting, it is useful for determiningwhether the vehicle was running or stopped, the en-gine was warmed up or not, the air–fuel ratio waslean or rich, etc. at the time of the malfunction.
Priorities for troubleshooting:If troubleshooting priorities for multiple DTCs are given in theapplicable DTC chart, these should be followed.If no instructions are given troubleshoot DTCs according to thefollowing priorities.
(1) DTCs other than fuel trim malfunction (DTCsP0171, P0172, P0174 and P0175) and misfire(DTCs P0300 – P0304).
(2) Fuel trim malfunction (DTCs P0171, P0172, P0174and P0175).
(3) Misfire (DTCs P0300 – P0304).
A04550
DLC3
43 65 87
109
21
1211 1513 1614
A13068
–DIAGNOSTICS ENGINEDI–5
169Author: Date:
2000 MR2 (RM760U)
(b) Check the DLC3.The vehicle’s ECM uses ISO 9141–2 for communication.The terminal arrangement of DLC3 complies with SAEJ1962 and matches the ISO 9141–2 format.
Terminal No. Connection/Voltage or Resistance Condition
7 Bus Line/Pulse generation During transmission
4 Chassis Ground ↔ Body Ground/1 Ω or less Always
5 Signal Ground ↔ Body Ground/1 Ω or less Always
16 Battery Positive ↔ Body Ground/9 – 14 V Always
HINT:If your display shows UNABLE TO CONNECT TO VEHICLEwhen you have connected the cable of the OBD II scan tool orTOYOTA hand–held tester to the DLC3, turned the ignitionswitch ON and operated the scan tool, there is a problem on thevehicle side or tool side. If communication is normal when the tool is connected to
another vehicle, inspect the DLC3 on the original vehicle. If communication is still not possible when the tool is con-
nected to another vehicle, the problem is probably in thetool itself, so consult the Service Department listed in thetool’s instruction manual.
2. INSPECT DIAGNOSIS (Normal Mode)(a) Check the MIL.
(1) The MIL comes on when the ignition switch is turnedON and the engine is not running.
HINT:If the MIL does not light up, troubleshoot the combination meter(See page BE–2).
(2) When the engine started, the MIL should go off. Ifthe lamp remains on, the diagnosis system has de-tected a malfunction or abnormality in the system.
(b) Check the DTC.NOTICE: If there is no DTC in the normal mode, check the 1st
trip DTC using continuous Test Results function(Mode 7 for SAE J1979) on the OBD II scan tool orTOYOTA hand–held tester.
DI–6–DIAGNOSTICS ENGINE
170Author: Date:
2000 MR2 (RM760U)
TOYOTA hand–held tester only:When the diagnosis system is switched from the nor-mal mode to the check mode, it erases all DTCs andfreezed frame data recorded in the normal mode. Sobefore switching modes, always check the DTCs andfreezed frame data, and note them down.(1) Prepare the OBD II scan tool (complying with SAE
J1978) or TOYOTA hand–held tester.(2) Connect the OBD II scan tool or TOYOTA hand–
held tester to DLC3.(3) Turn the ignition switch ON and push the OBD II
scan tool or TOYOTA hand–held tester switch ON.(4) Use the OBD II scan tool or TOYOTA hand–held
tester to check the DTCs and freezed frame data,note them down (For operating instructions, see theOBD II scan tool’s instruction book).
If there is no DTC in the normal mode, check the 1st trip DTCusing Continuous Test Results function (Mode 7 for SAE J1979)on the OBDII scan tool or TOYOTA hand–held tester.
(5) See page DI–3 to confirm the details of the DTCs.NOTICE: When simulating symptoms with an OBD II scan tool
(excluding TOYOTA hand–held tester) to check theDTCs, use the normal mode. For code on the DTCchart subject to ”2 trip detection logic”, perform thefollowing either action.
Turn the ignition switch OFF after the symptom issimulated the 1st time. Then repeat the simulationprocess again. When the problem has been simulatedtwice, the MIL lights up and the DTCs are recorded inthe ECM.
Check the 1st trip DTC using Mode 7 (Continuous TestResults) for SAE J1979.
(c) Clear the DTC.The DTC and freezed frame data will be erased by eitheraction.(1) Operating the OBD II scan tool (complying with SAE
J1978) or TOYOTA hand–held tester to erase thecodes (For operating instructions, see the OBD IIscan tool’s instruction book).
(2) Disconnecting the battery terminals or EFI1 fuse.NOTICE:If the TOYOTA hand–held tester switches the ECM from thenormal mode to the check mode or vise–verse, or if theignition switch is turned from ON to ACC or OFF during thecheck mode, the DTCs and freezed frame data will beerased.
FI3605
ON
OFF
Flashing
0.13 Second
–DIAGNOSTICS ENGINEDI–7
171Author: Date:
2000 MR2 (RM760U)
3. INSPECT DIAGNOSIS (Check Mode)HINT:TOYOTA hand–held tester only:Compared to the normal mode, the check mode has an in-creased sensitivity to detect malfunctions.Furthermore, the same diagnostic items which are detected inthe normal mode can also be detected in the check mode.(a) Check the DTC.
(1) Initial conditions Battery positive voltage 11V or more Throttle valve fully closed Transmission in neutral position A/C switched OFF
(2) Turn the ignition switch OFF.(3) Prepare the TOYOTA hand–held tester.(4) Connect the TOYOTA hand–held tester to the
DLC3.(5) Turn the ignition switch ON and push the TOYOTA
hand–held tester switch ON.
(6) Switch the TOYOTA hand–held tester from the nor-mal mode to the check mode.
(7) Check if the MIL blinks.NOTICE:If the TOYOTA hand–held tester switches the ECM from thenormal mode to the check mode or vise–versa, or if theignition switch is turned from ON to ACC or LOCK duringthe check mode, the DTCs and freezed frame data will beerased.
(8) Start the engine (The MIL goes out after the enginestart).
(9) Simulate the conditions of the malfunction de-scribed by the customer.
NOTICE:Leave the ignition switch ON until you have checked theDTC, etc.
(10) After simulating the malfunction conditions, use theTOYOTA hand–held tester diagnosis selector tocheck the DTCs and freezed frame data, etc.
HINT:Take care not to turn the ignition switch OFF. Turning the ignitionswitch OFF switches the diagnosis system from check mode tonormal mode. So all DTCs, etc. are erased.
(11) After checking the DTC, inspect the applicable cir-cuit.
N09348
Vehicle Harness
Interface Box
TOYOTA Break–Out–Box
ECM
TOYOTA Hand–held Tester
DI–8–DIAGNOSTICS ENGINE
172Author: Date:
2000 MR2 (RM760U)
(b) The ECM terminal values measurement using TOYOTAbreak–out–box and TOYOTA hand–held tester(1) Hook up the TOYOTA break–out–box and TOYOTA
hand–held tester to the vehicle.(2) Read the ECM input/output values by following the
prompts on the tester screen.HINT: The TOYOTA Hand–held tester has a ”Snapshot” func-
tion.This records the measured values and is effective inthe diagnosis of intermittent problems.
Please refer to the TOYOTA hand–held tester/TOYOTAbreak–out–box operator’s manual for further details.
4. FAIL–SAFE CHARTIf any of the following codes is recorded, the ECM enters fail–safe mode.
DTC No. Fail–Safe Operation Fail–Safe Deactivation Conditions
P0110 Intake air temperature is fixed at 20°C (68°F) Returned to normal condition
P0115 Engine coolant temperature is fixed at 80°(176°F) Returned to normal condition
P0120 VTA is fixed at 0°
The following condition must be repeated at least 2 times
consecutively
VTA 0.1 V and 0.95 V
P0325 Max. timing retardation Ignition switch OFF
P1300 Fuel cut IGF signal is detected for 4 consecutive ignitions
5. CHECK FOR INTERMITTENT PROBLEMSTOYOTA hand–held tester only:By putting the vehicle’s ECM in the check mode, 1 trip detection logic is possible instead of 2 trip detectionlogic and sensitivity to detect open circuits is increased. This makes it easier to detect intermittent problems.
(1) Clear the DTC (See step 2).(2) Set the check mode (See step 3).(3) Perform a simulation test (See page IN–18).(4) Check the connector and terminal (See page IN–28).(5) Handle the connector (See page IN–28).
6. BASIC INSPECTIONWhen the malfunction code is not confirmed in the DTC check, troubleshooting should be performed in orderfor all possible circuits to be considered as the causes of the problems. In many cases, by carrying out thebasic engine check shown in the following flow chart, the location causing the problem can be found quicklyand efficiently. Therefore, use of this check is essential in engine troubleshooting.
1 Is battery positive voltage 11 V or more when engine is stopped?
NO Charge or replace battery.
YES
2 Is engine cranked?
EM9891
Outside
Inside
–DIAGNOSTICS ENGINEDI–9
173Author: Date:
2000 MR2 (RM760U)
NO Proceed to problems table on page DI–21.
YES
3 Does engine start?
NO Go to step 7.
YES
4 Check air filter.
PREPARATION:Remove the air filter.CHECK:Visually check that the air filter is not dirty or excessive oily.HINT:If necessary, clean the air filter with compressed air. First blowfrom inside thoroughly, then blow from outside of the air filter.
NG Repair or replace.
OK
5 Check idle speed.
PREPARATION:(a) Warm up the engine to normal operating temperature.(b) Switch off all the accessories.(c) Switch off the A/C.(d) Shift the transmission into the neutral position.(e) Connect the OBD II scan tool or TOYOTA hand–held tester to the DLC3 on the vehicle.CHECK:Use the CURRENT DATA to check the idle speed.OK:
Idle speed: 800 ± 50 rpm
NG Proceed to problem symptoms table on pageDI–21.
A12716A11848
A12893
SST
DLC3
TC (13)
CG (4)
B10046
DI–10–DIAGNOSTICS ENGINE
174Author: Date:
2000 MR2 (RM760U)
OK
6 Check ignition timing.
PREPARATION:(a) Warm up the engine to normal operating temperature.(b) Shift the transmission into the neutral position.(c) Keep the engine speed at idle.(d) Using SST, connect terminals 13 (TC) and 4 (CG) of the
DLC3.SST 09843–18040
(e) Connect the timing light (See page EM–9).CHECK:Check the ignition timing.OK:
Ignition timing: 8 – 12 ° BTDC at idle
NG Proceed to page IG–1, continue to troubleshoot.
OK
Proceed to problem symptoms table on pageDI–21.
7 Check fuel pressure.
PREPARATION:(a) Be sure that enough fuel is in the tank.(b) Connect the TOYOTA hand–held tester to the DLC3.(c) Turn the ignition switch ON and push the TOYOTA hand–
held tester main switch ON.(d) Use the ACTIVE TEST mode to operate the fuel pump.(e) Please refer to the TOYOTA hand–held tester operator’s
manual for further details.(f) If you have no TOYOTA hand–held tester, connect the
positive (+) and negative (–) leads from the battery to thefuel pump connector (See page SF–7).
A10094
–DIAGNOSTICS ENGINEDI–11
175Author: Date:
2000 MR2 (RM760U)
CHECK:Check for fuel pressure in the fuel inlet hose when it is pinchedoff.HINT:At this time, you will hear a fuel flowing noise.
NG Proceed to page SF–7, continue to trouble-shoot.
OK
8 Check for spark.
PREPARATION:(a) Remove the ignition coil with igniter.(b) Remove the spark plug.(c) Install the spark plug to the ignition coil with igniter.(d) Disconnect the 4 injector connectors.(e) Ground the spark plug.CHECK:Check if spark occurs while the engine is being cranked.NOTICE: To prevent excess fuel from being injected from the
injectors during this test, don’t crank the engine formore than 5 – 10 seconds at a time.
Do not crash the electrode gap.
NG Proceed to page IG–1, continue to troubleshoot.
OK
Proceed to problem symptoms table on pageDI–21.
DI–12–DIAGNOSTICS ENGINE
176Author: Date:
2000 MR2 (RM760U)
7. ENGINE OPERATING CONDITIONNOTICE:The values given below for ”Normal Condition” are representative values, so a vehicle may still benormal even if its value varies from those listed here. So do not decide whether a part is faulty ornot solely according to the ”Normal Condition” here.(a) CARB mandated signals.
TOYOTA hand–held tester display Measurement Item Normal Condition*
FUEL SYS #1
Fuel System Bank 1
OPEN: Air–fuel ratio feedback stopped
CLOSED: Air–fuel ratio feedback operating
Idling after warming up: CLOSED
FUEL SYS #2
Fuel System Bank 2
OPEN: Air–fuel ratio feedback stopped
CLOSED: Air–fuel ratio feedback operating
Idling after warming up: CLOSED
CALC LOAD
Calculator Load:
Current intake air volume as a proportion of max.
intake air volume
Idling: 11.3 – 16.0 %
Racing without load (2,500rpm): 12.3 – 17.9 %
COOLANT TEMP Engine Coolant Temp. Sensor Value After warming up: 80 – 95°C (176 – 203°F)
SHORT FT #1 Short–term Fuel Trim Bank 1 0 ± 20 %
LONG FT #1 Long–term Fuel Trim Bank 1 0 ± 20 %
SHORT FT #2 Short–term Fuel Trim Bank 2 0 ± 20 %
LONG FT #2 Long–term Fuel Trim Bank 2 0 ± 20 %
ENGINE SPD Engine SpeedIdling:
650 – 750 rpm
VEHICLE SPD Vehicle Speed Vehicle stopped: 0 km/h (0 mph)
IGN ADVANCEIgnition Advance:
Ignition Timing of Cylinder No. 1Idling: BTDC 8 – 12°
INTAKE AIR Intake Air Temp. Sensor Value Equivalent to ambient temp.
MAF Air Flow Rate Through Mass Air Flow Meter
Idling:
1.4 – 2.0 gm/sec.
Racing without load (2,500 rpm):
5.4 – 7.9 gm/sec.
THROTTLE POSVoltage Output of Throttle Position Sensor Calcu-
lated as a percentage: 0 V → 0 %, 5 V → 100 %
Throttle fully closed: 6 – 16 %
Throttle fully open: 64 – 98 %
O2S B1 S1Voltage Output of Heated Oxygen Sensor Bank 1
Sensor 1Idling: 0.1 – 0.9 V
O2S B2 S1Voltage Output of Heated Oxygen Sensor Bank 2
Sensor 1Idling: 0.1 – 0.9 V
O2FT B1 S1Heated Oxygen Sensor Fuel Trim Bank 1 Sensor
1 (Same as SHORT FT #1)0 ± 20 %
O2FT B2 S1Heated Oxygen Sensor Fuel Trim Bank 2 Sensor
1 (Same as SHORT FT #1)0 ± 20 %
O2S B1 S2Voltage Output of Heated Oxygen Sensor Bank 1
Sensor 2Driving at 50 km/h (31 mph): 0.1 – 0.9 V
*: If no conditions are specifically stated for ”ldling”, it means the shift lever is at neutral position, the A/Cswitch is OFF and all accessory switches are OFF.
–DIAGNOSTICS ENGINEDI–13
177Author: Date:
2000 MR2 (RM760U)
(b) TOYOTA Enhanced Signals.
TOYOTA hand–held tester display Measurement Item Normal Condition*
MISFIRE RPM Engine RPM for first misfire range Misfire 0: 0 rpm
MISFIRE LOAD Engine load for first misfire range Misfire 0: 9 g/r
INJECTOR Fuel injection time for cylinder No. 1 Idling: 1.1 – 2.1 ms
IAC DUTY RATIOIntake Air Control Valve Duty Ratio
Opening ratio rotary solenoid type IAC valveIdling: 25 – 35 %
STARTER SIG Starter Signal Cranking: ON
CTP SW Closed Throttle Position Signal Throttle fully closed: ON
A/C SIG A/C Switch Signal A/C ON: ON
ELECTCL LOAD SIG Electrical Load Signal Defogger S/W ON: ON
STOP LIGHT SW Stop Light Switch Signal Stop light switch ON: ON
PS OIL PRESS SW Power Steering Oil Pressure Switch Signal Turning steering wheel: ON
FC IDLFuel Cut Idle: Fuel cut when throttle valve fully
closed, during decelerationFuel cut operating: ON
FC TAU Fuel Cut TAU: Fuel cut during very light load Fuel cut operating: ON
CYL#1, CYL#2, CYL#3, CYL#4 Abnormal revolution variation for each cylinder 0 %
IGNITIONTotal number of ignition for every 1,000 revolu-
tions0 – 2,000
FUEL PUMP Fuel Pump Signal Idling: ON
A/C MAG CLUTCH A/C switch signal A/C ON: ON
EVAP (PURGE) VSV EVAP VSV signal VSV operating: ON
VVT CTRL VVT control signal VVT operating: ON
INTAKE CTRL VSV Intake control VSV signal VSV operating: ON
TOTAL FT B1Total Fuel Trim Bank 1: Average value for fuel
trim system of bank 1Idling: 0.8 – 1.2 V
TOTAL FT B2Total Fuel Trim Bank 2: Average value for fuel
trim system of bank 2Idling: 0.8 – 1.2 V
O2 LR B1 S1
Heated Oxygen Sensor Lean Rich Bank 1 Sen-
sor 1 Response time for oxygen sensor output to
switch from lean to rich
Idling after warming up: 0 – 1,000 msec.
O2 LR B2 S1
Heated Oxygen Sensor Lean Rich Bank 2 Sen-
sor 1 Response time for oxygen sensor output to
switch from lean to rich
Idling after warming up: 0 – 1,000 msec.
O2 RL B1 S1
Heated Oxygen Sensor Rich Lean Bank 1 Sen-
sor 1 Response time for oxygen sensor output to
switch from rich to lean
Idling after warming up: 0 – 1,000 msec.
O2 RL B2 S1
Heated Oxygen Sensor Rich Lean Bank 2 Sen-
sor 1 Response time for oxygen sensor output to
switch from rich to lean
Idling after warming up: 0 – 1,000 msec.
*: If no conditions are specifically stated for ”ldling”, it means the shift lever is at neutral position, the A/Cswitch is OFF and all accessory switches are OFF.
DI37T–04
DI–14–DIAGNOSTICS ENGINE
178Author: Date:
2000 MR2 (RM760U)
DIAGNOSTIC TROUBLE CODE CHARTHINT:Parameters listed in the chart may not be exactly the same as your reading due to the type of instrumentor other factors.If a malfunction code is displayed during the DTC check in check mode, check the circuit for the codes listedin the table below. For details of each code, turn to the page referred to under the ’’See page ’’ for the respec-tive ’’DTC No.’’ in the DTC chart.SAE CONTROLLED:
DTC No. Detection Item Trouble Area MIL* Memory
P0100
(DI–23)
Mass Air Flow Circuit Malfunc-
tion
Open or short in mass air flow meter circuit
Mass air flow meter
ECM
P0101
(DI–27)
Mass Air Flow Circuit Range/
Performance ProblemMass air flow meter
P0110
(DI–28)
Intake Air Temp. Circuit Malfunc-
tion
Open or short in intake air temp. sensor circuit
Intake air temp. sensor (built into mass air flow meter)
ECM
P0115
(DI–32)
Engine Coolant Temp. Circuit
Malfunction
Open or short in engine coolant temp. sensor circuit
Engine coolant temp. sensor
ECM
P0116
(DI–36)
Engine Coolant Temp. Circuit
Range/Performance Problem
Cooling system
Engine coolant temp. sensor
P0120
(DI–37)
Throttle/Pedal Position Sensor/
Switch ”A” Circuit Malfunction
Open or short in throttle position sensor circuit
Throttle position sensor
ECM
P0121
(DI–41)
Throttle/Pedal Position Sensor/
Switch ”A” Circuit Range/Perfor-
mance Problem
Throttle position sensor
P0125
(DI–42)
Insufficient Coolant Temp. for
Closed Loop Fuel Control
Open or short in heated oxygen sensor (bank 1, 2 sensor 1)
circuit
Heated oxygen sensor (bank 1, 2 sensor 1)
Air induction system
Fuel pressure
Injector
Gas leakage on exhaust system
ECM
P0130
(DI–47)
Oxygen Sensor Circuit Malfunc-
tion (Bank 1 Sensor 1)
Open or short in heated oxygen sensor circuit
Heated oxygen sensor
Air induction system
Fuel pressure
Injector
ECM
P0133
(DI–51)
Oxygen Sensor Circuit Slow Re-
sponse (Bank 1 Sensor 1)
Open or short in heated oxygen sensor circuit
Heated oxygen sensor
Air induction system
Fuel pressure
Injector
ECM
P0135
(DI–54)
Oxygen Sensor Heater Circuit
Malfunction (Bank 1 Sensor 1)
Open or short in heater circuit of heated oxygen sensor
Heated oxygen sensor heater
ECM
P0136
(DI–56)
Oxygen Sensor Circuit Malfunc-
tion (Bank 1 Sensor 2)
Open or short in heated oxygen sensor circuit
Heated oxygen sensor
–DIAGNOSTICS ENGINEDI–15
179Author: Date:
2000 MR2 (RM760U)
P0141
(DI–54)
Oxygen Sensor Heater Circuit
Malfunction (Bank 1 Sensor 2)Same as DTC No. P0135
P0150
(DI–47)
Oxygen Sensor Circuit Malfunc-
tion (Bank 2 Sensor 1)Same as DTC No. P0130
P0153
(DI–51)
Oxygen Sensor Circuit Slow Re-
sponse (Bank 2 Sensor 1)Same as DTC No. P0133
P0155
(DI–54)
Oxygen Sensor Heater Circuit
Malfunction (Bank 2 Sensor 1)Same as DTC No. P0135
P0171
(DI–58)
System too Lean (Fuel Trim)
(Bank 1)
Air induction system
Injector blockage
Mass air flow meter
Engine coolant temp. sensor
Fuel pressure
Gas leakage on exhaust system
Open or short in heated oxygen sensor (bank 1 sensor 1)
circuit
Heated oxygen sensor (bank 1 sensor 1)
ECM
P0172
(DI–58)
System too Rich (Fuel Trim)
(Bank 1)
Injector leak, blockage
Mass air flow meter
Engine coolant temp. sensor
Ignition system
Fuel pressure
Gas leakage on exhaust system
Open or short in heated oxygen sensor (bank 1, sensor 1)
circuit
Heated oxygen sensor (bank 1, sensor 1)
ECM
P0174
(DI–58)
System too Lean (Fuel Trim)
(Bank 2)Same as the DTC No. P0171
P0175
(DI–58)
System too Rich (Fuel Trim)
(Bank 2)Same as the DTC No. P0172
P0300
(DI–63)
Random/Multiple Cylinder Misfire
DetectedOpen or short in engine wire
Connector connection
P0301
(DI–63)Cylinder 1 Misfire Detected
Vacuum hose connection
Ignition system
InjectorP0302
(DI–63)Cylinder 2 Misfire Detected
Injector
Fuel pressure
Mass air flow meter
P0303
(DI–63)Cylinder 3 Misfire Detected
Engine coolant temp. sensor
Compression pressure
Valve clearanceP0304
(DI–63)Cylinder 4 Misfire Detected
Valve clearance
Valve timing
ECM
P0325
(DI–68)
Knock Sensor 1 Circuit Malfunc-
tion (Bank 1)
Open or short in knock sensor circuit
Knock sensor (looseness)
ECM
P0335
(DI–71)
Crankshaft Position Sensor ”A”
Circuit Malfunction
Open or short in crankshaft position sensor circuit
Crankshaft position sensor
Crank angle sensor plate
ECM
P0340
(DI–73)
Camshaft Position Sensor Cir-
cuit Malfunction
Open or short in camshaft position sensor circuit
Camshaft position sensor
Intake Camshaft
ECM
DI–16–DIAGNOSTICS ENGINE
180Author: Date:
2000 MR2 (RM760U)
P0420
(DI–75)
Catalyst System Efficiency Be-
low Threshold (Bank 1)
Gas leakage on exhaust system
Heated oxygen sensor
Three–way catalytic converter
P0440
(DI–78)
Evaporative Emission Control
System Malfunction
Hose or tube cracked, holed, damaged or loose seal ((3) in
Fig.1)
Fuel tank cap incorrectly installed
Fuel tank cap cracked or damaged
Vacuum hose cracked, holed, blocked, damaged or discon-
nected ((1) or (2) in Fig. 1)
Fuel tank cracked, holed or damaged
Charcoal canister cracked, holed or damaged
Open or short in vapor pressure sensor circuit
Vapor pressure sensor
Fuel tank over fill check valve cracked or damaged
ECM
P0441
(DI–84)
Evaporative Emission Control
System Incorrect Purge Flow
Vacuum hose cracked, holed, blocked damaged or discon-
nected((1), (2), (3),(4),(5), (6), (7), (8), (9), (10) and (11) in
Fig.1)
Fuel tank cap incorrectly installed
Fuel tank cap cracked or damaged
Open or short in vapor pressure sensor circuit
Vapor pressure sensor
Open or short in VSV circuit for EVAP
VSV for EVAP
Open or short in VSV circuit for pressure switching valve
VSV for pressure switching valve
Fuel tank cracked, holed or damaged
Charcoal canister cracked, holed or damaged
Fuel tank over fill check valve cracked or damaged
ECM
P0446
(DI–84)
Evaporative Emission Control
System Vent Control MalfunctionSame as DTC No. P0441
P0450
(DI–101)
Evaporative Emission Control
System Pressure Sensor Mal-
function Open or short in vapor pressure sensor circuit
V
P0451
(DI–101)
Evaporative Emission Control
System Pressure Sensor Range/
Performance
Vapor pressure sensor
ECM
P0500
(DI–103)
Vehicle Speed Sensor Malfunc-
tion
Combination meter
Open or short in vehicle speed sensor circuit
Vehicle speed sensor
ECM
P0505
(DI–106)Idle Control System Malfunction
Open or short in IAC valve circuit
IAC valve is stuck or closed
Open or short in A/C switch circuit
Air induction system
ECM
*: MIL lights up
–DIAGNOSTICS ENGINEDI–17
181Author: Date:
2000 MR2 (RM760U)
MANUFACTURER CONTROLLED:
DTC No.
(See Page)Detection Item Trouble Area MIL* Memory
P1300
(DI–109)Igniter Circuit Malfunction (No. 1)
Ignition system
Open or short in IGF and IGT1 circuit from No. 1 ignition coil
with igniter to ECM
No. 1 ignition coil with igniter
ECM
P1305
(DI–109)Igniter Circuit Malfunction (No. 2)
Ignition system
Open or short in IGF and IGT2 circuit from No. 2 ignition coil
with igniter to ECM
No. 2 ignition coil with igniter
ECM
P1310
(DI–109)Igniter Circuit Malfunction (No. 3)
Ignition system
Open or short in IGF and IGT3 circuit from No. 3 ignition coil
with igniter to ECM
No. 3 ignition coil with igniter
ECM
P1315
(DI–109)Igniter Circuit Malfunction (No. 4)
Ignition system
Open or short in IGF and IGT4 circuit from No. 4 ignition coil
with igniter to ECM
No. 4 ignition coil with igniter
ECM
P1335
(DI–115)
Crankshaft Position Sensor Cir-
cuit Malfunction (During engine
running)
Same as DTC No. P0335 –
P1346
(DI–116)
VVT Sensor/Camshaft Position
Sensor Circuit Range/Perfor-
mance Problem (Bank 1)
Mechanical system (Jumping teeth of timing chain, chain
stretched)
ECM
P1349
(DI–117)
VVT System Malfunction (Bank
1)
Valve timing
OCV
VVT controller assembly
ECM
P1600
(DI–123)ECM BATT Malfunction
Open in back up power source circuit
ECM
P1645
(DI–125)Body ECU Malfunction
Body ECU
A/C ECU
Vane pump assembly with motor
ABS ECU
Combination meter
Air bag sensor assembly
Communication bus
– –
P1656
(DI–127)
OCV Circuit Malfunction (Bank
1)
Open or short in OCV circuit
OCV
ECM
*: MIL lights up. – MIL does not light up.
DI37U–03
A12058
A13055 A12811
Mass Air Flow Meter
CharcoalCanister ECM
IAC Valve
Vapor PressureSensor
VSV for EVAPVSV for CCV
VSV for Pressure Switching Valve
Engine Coolant Temp. Sensor
Starter Relay(Marking: ST)
Engine Room R/B
Circuit Opening Relay(Marking: C/OPN)
EFI Main Relay(Marking: EFI MAIN)
A/C MagneticClutch Relay(Marking: A/C COMP)
IG2 Relay(Marking: IG2)
Knock Sensor
Ignition Coil with Igniter
OCVCrankshaftPositionSensor
DLC3
Oxygen Sensor(Bank 1 Sensor 2)
Oxygen Sensor(Bank 1 Sensor 1)
Throttle Position Sensor
Injector
Camshaft Position Sensor
Oxygen Sensor(Bank 2 Sensor 1)
Combination Meter
FL Block, J/B No. 1Three–wayCatalyticConverter
Fuel Pump
R/B No.3, J/B No.3
IG1 Relay(Marking: IG1)
DI–18–DIAGNOSTICS ENGINE
182Author: Date:
2000 MR2 (RM760U)
PARTS LOCATION
DI37V–05
A10774
E5 E4 E3ECM Terminals
E2
31 30 29 28 27
17192021
2223242526
11121314
123456789
10151618
1234567
8910111213141516
182021222324 1719
123456789
1012 1113141516171819
202123 222426 252728
1234567
89101112131415
16171819202122
–DIAGNOSTICS ENGINEDI–19
183Author: Date:
2000 MR2 (RM760U)
TERMINALS OF ECM
Symbols (Terminal No.) Wiring Color Condition STD Voltage (V)
BATT (E2–1) – E1 (E4–17) B–Y – BR Always 9 – 14
IGSW (E2–8) – E1 (E4–17) B–R – BRIG it h ON 9 14
+B (E2–16) – E1 (E4–17) B – BRIG switch ON 9 – 14
VC (E4–2) – E2 (E4–18) L–R – BR IG switch ON 4.5 – 5.5
VTA (E4 23) E2 (E4 18) B W BRIG switch ON, Accelerator pedal fully closed 0.3 – 1.0
VTA (E4–23) – E2 (E4–18) B–W – BRIG switch ON, Accelerator pedal fully open 3.2 – 4.8
THA (E4–22) – E2 (E4–18) Y–B – BR Idling, Intake air temp. 20°C (68°F) 0.5 – 3.4
THW (E4–14) – E2 (E4–18) R–L – BR Idling, Water temp. 80°C (176°F) 0.2 – 1.0
STA (E3–11) – E1 (E4–17) B – BR Shift position in neutral, Ignition SW START 6.0 or more
#10 (E5–1) – E01 (E5–21)
#20 (E5 2) E01 (E5 21)
B–W – W–R
B W BIG switch ON 9 – 14
#20 (E5–2) – E01 (E5–21)
#30 (E5–3) – E01 (E5–21)
#40 (E5–4) – E01 (E5–21)
B – W–B
L – W–B
W – W–BIdling
Pulse generation
(See page DI–63)
IGT1 (E5–10) – E1 (E4–17)
IGT2 (E5–11) – E1 (E4–17)
IGT3 (E5–12) – E1 (E4–17)
IGT4 (E5–13) – E1 (E4–17)
B – BR
L – BR
L–W – BR
L – BR
IdlingPulse generation
(See page DI–109)
IG switch ON 4.5 – 5.5
IGF (E5–25) – E1 (E4–17) B–Y – BRIdling
Pulse generation
(See page DI–109)
G2 (E4–15) – NE– (E4–24) W – BIdli
Pulse generation
NE+ (E4–16) – NE– (E4–24) W – BIdling
Pulse generation
(See page DI–71)
MREL (E3–21) – E1 (E4–17) GR – BR IG switch ON 9 – 14
FC (E2–3) – E1 (E4–17) G–R – BR IG switch ON 9 – 14
STP (E3 6) E1 (E4 17) G BRBrake pedal is depressed 9 – 14
STP (E3–6) – E1 (E4–17) G – BRBrake pedal is released Below 1.5
OX1A (E4–12) – E1 (E4–17) B – BR Maintain engine speed at 2,500 rpm for 90 sec. after warming upPulse generation
(See page DI–42)
OX2A (E4–21) – E1 (E4–17) B – BR Maintain engine speed at 2,500 rpm for 90 sec. after warming upPulse generation
(See page DI–42)
OX1B (E4–9) – E1 (E4–17) B – BR Maintain engine speed at 2,500 rpm for 3 min. after warming upPulse generation
(See page DI–42)
HT1A (E4–3) – E01 (E4–6)
HT1B (E4 8) E01 (E4 6)
B–Y – BR
L B BRIdling Below 3.0
HT1B (E4–8) – E01 (E4–6)
HT2A (E4–5) – E01 (E4–6)
L–B – BR
B–W – BR IG switch ON 9 – 14
KNK1 (E5–27) – E1 (E4–17) W – BR Maintain engine speed at 4,000 rpm after warming upPulse generation
(See page DI–68)
DI–20–DIAGNOSTICS ENGINE
184Author: Date:
2000 MR2 (RM760U)
TC (E3–5) – E1 (E4–17) P–L – BR IG switch ON 9 – 14
W (E2 15) E01 (E4 6) Y R BRIdling 9 – 14
W (E2–15) – E01 (E4–6) Y–R – BRIG switch ON Below 3.0
OCV+ (E5–24)
– OCV– (E5–23)R – W IG switch ON
Pulse generation
(See page DI–117)
EVP1 (E4–4) – E01 (E4–6) W – BR IG switch ON 9 – 14
RSO (E5–18) – E1 (E4–17) G – BR IG switch ON 9 – 14
TBP (E3–23) – E01 (E4–6) L–W – BR IG switch ON 3.0 – 3.6
PTNK (E2–4) – E2 (E4–18) G–B – BR IG switch ON 3.0 – 3.6
SPD (E3–22) – E1 (E4–17) V–W – BR IG switch ON 9 – 14
PRE (E3 18) E1 (E4 17) W L BRRefrigerant pressure is between 196 kPa and 1340 kPa 9 – 14
PRE (E3–18) – E1 (E4–17) W–L – BRRefrigerant pressure is less than 196 kPa, more than 1340 kPa –
ACMG (E2 12) E01 (E4 6) L BRIdling, Magnetic clatch is ON below 1.0
ACMG (E2–12) – E01 (E4–6) L – BRIdling, Magnetic clatch is OFF 9 – 14
LCK1 (E3 28) E1 (E4 17) W R BRIdling, A/C switch is ON 9 – 14
LCK1 (E3–28) – E1 (E4–17) W–R – BRIdling, A/C switch is OFF –
DI37W–04
–DIAGNOSTICS ENGINEDI–21
185Author: Date:
2000 MR2 (RM760U)
PROBLEM SYMPTOMS TABLEWhen the malfunction is not confirmed in the diagnostic trouble code check and the problem still can not beconfirmed in the basic inspection, proceed to this problem symptoms table and troubleshoot according tothe numbered order given below.
Symptom Suspected Area See page
Engine does not crank (Does not start)
7. Starter
8. Starter relay
9. Body ECU
ST–7
ST–17
DI–357
No initial combustion (Does not start)
1. ECM power source circuit
2. Ignition coil with igniter
3. Fuel control circuit
4. Injector circuit
DI–132
DI–109
DI–140
DI–63
No complete combustion (Does not start)
1. Ignition coil with igniter
2. Fuel control circuit
3. Injector circuit
DI–109
DI–140
DI–63
Engine cranks normally (Difficult to start)
1. Starter signal circuit
2. Ignition coil with igniter
3. Spark plug
4. Compression
5. Injector circuit
6. Fuel control circuit
7. IAC valve circuit
DI–137
DI–109
IG–1
EM–3
DI–63
DI–140
DI–106
Cold engine (Difficult to start)
1. Starter signal circuit
2. Injector circuit
3. Ignition coil with igniter
4. Spark plug
5. Fuel control circuit
6. IAC valve circuit
DI–137
DI–63
DI–109
IG–1
DI–140
DI–106
Hot engine (Difficult to start)
1. Starter signal circuit
2. Injector circuit
3. Ignition coil
4. Spark plug
5. Fuel control circuit
6. IAC valve circuit
DI–137
DI–63
DI–109
IG–1
DI–140
DI–106
High engine idle speed (Poor idling)
1. ECM power source circuit
2. Back up power source circuit
3. IAC valve circuit
DI–132
DI–123
DI–106
Low engine idle speed (Poor idling)
1. Injector circuit
2. Back up power source circuit
3. Fuel control circuit
4. IAC valve circuit
DI–63
DI–123
DI–140
DI–106
Rough idling (Poor idling)
1. IAC valve circuit
2. Injector circuit
3. Fuel control circuit
4. Ignition coil with igniter
5. Compression
DI–106
DI–63
DI–140
DI–109
EM–3
Hunting (Poor idling)
1. ECM power source circuit
2. Fuel control circuit
3. IAC valve circuit
DI–132
DI–140
DI–106
Hesitation/Poor acceleration (Poor driveability)
1. Injector circuit
2. Ignition coil with igniter
3. Fuel control circuit
DI–63
DI–109
DI–140
DI–22–DIAGNOSTICS ENGINE
186Author: Date:
2000 MR2 (RM760U)
Muffler explosion, after fire (Poor driveability)
1. Ignition coil
2. Spark plug
3. Injector circuit
IG–1
IG–1
DI–63
Surging (Poor driveability)1. Spark plug
2. Injector circuit
IG–1
DI–63
Engine stall (Soon after starting)1. Fuel control circuit
2. IAC valve circuit
DI–140
DI–106
Engine stall (After accelerator pedal depressed)
1. Injector circuit
2. IAC valve circuit
3. ECM
DI–63
DI–106
IN–28
Engine stall (After accelerator pedal released)1. ECM
2. IAC valve circuit
IN–28
DI–106
Engine stall (During A/C operation)1. A/C signal circuit (Compressor circuit)
2. ECM
DI–150
IN–28
DI09B–08
FI6929
A13069 A12542
B+
ThermistorPower Transistor
Platinum Hot Wire
BOutput
A
Voltage
Platinum Hot Wire
Thermistor
Air
Mass Air Flow Meter
Intake Air Temp. Sensor
–DIAGNOSTICS ENGINEDI–23
187Author: Date:
2000 MR2 (RM760U)
CIRCUIT INSPECTION
DTC P0100 Mass Air Flow Circuit Malfunction
CIRCUIT DESCRIPTIONThe mass air flow meter uses a platinum hot wire. The hot wire air flow meter consists of a platinum hot wire,thermistor and a control circuit installed in a plastic housing. The hot wire air flow meter works on the principlethat the hot wire and thermistor located in the intake air bypass of the housing detect any changes in theintake air temperature.The hot wire is maintained at the set tempreature by controlling the current flow through the hot wire. Thiscurrent flow is then measured as the output voltage of the air flow meter.The circuit is constructed so that the platinum hot wire and thermistor provide a bridge circuit, with the powertransistor controlled so that the potential of A and B remains equal to maintain the set temperature.
DTC No. DTC Detection Condition Trouble Area
P0100Open or short in mass air flow meter circuit with more than 3
sec. engine speed 4,000 rpm or less
Open or short in mass air flow meter circuit
Mass air flow meter
ECM
HINT:After confirming DTC P0100, use the OBD II scan tool or TOYOTA hand–held tester to confirm the massair flow ratio from the CURRENT DATA.
Mass Air Flow Value (gm/sec.) Malfunction
0.0Mass air flow meter power source circuit open
VG circuit open or short
271.0 or more EVG circuit open
A12543
ECM
EVG
VG
B–R
M1Mass Air Flow Meter
1
E4
11E4
E2
2From Terminal 3 ofEFI MAIN Relay(See page DI–132) 3
1
V
BR
B
5
18E4
BC2
5B E2G
VG
E2
+B
DI–24–DIAGNOSTICS ENGINE
188Author: Date:
2000 MR2 (RM760U)
WIRING DIAGRAM
INSPECTION PROCEDUREHINT:Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze frame recordsthe engine conditions when the malfunction is detected. When troubleshooting, it is useful for determiningwhether the vehicle was running or stopped, the engine was warmed up or not, the air–fuel ratio was leanor rich, etc. at the time of the malfunction.
1 Connect OBD II scan tool or TOYOTA hand–held tester, and read value of massair flow rate.
PREPARATION:(a) Connect the OBD II scan tool or TOYOTA hand–held tester to the DLC3.(b) Turn the ignition switch ON and push the OBD II scan tool or TOYOTA hand–held tester main switch
ON.(c) Start the engine.CHECK:Read the mass air flow rate on the OBD II scan tool or TOYOTA hand–held tester.RESULT:
Type I Type II
Mass Air Flow Rate (gm/sec.) 0.0 271.0 or more
Type I Go to step 2.
Type II Go to step 5.
BE6653
P24310 A00099
ON
1
(+)
(–)
BE6653
A11492 A12720
VGSTART
(+) (–)
–DIAGNOSTICS ENGINEDI–25
189Author: Date:
2000 MR2 (RM760U)
2 Check voltage of mass air flow meter power source.
PREPARATION:(a) Disconnect the mass air flow meter connector.(b) Turn the ignition switch ON.CHECK:Measure the voltage between terminal 1 of the mass air flowmeter connector and body ground.OK:
Voltage: 9 – 14 V
NG Check for open in harness and connector be-tween EFI main relay (Marking: EFI MAIN) andmass air flow meter (See page IN–28).
OK
3 Check voltage between terminal VG of ECM connector and body ground.
PREPARATION:(a) Disconnect the ECM with connector from body panel
(See page SF–62).(b) Start the engine.CHECK:Measure the voltage between terminal VG of the ECM connec-tor and body ground while the engine is idling.OK:
Voltage: 1.1 – 1.5 V (Neutral position and A/C switch OFF)
OK Check and replace ECM (See page IN–28).
NG
4 Check for open and short in harness and connector between mass air flow meterand ECM (See page IN–28).
NG Repair or replace harness or connector.
OK
A11493
EVG
DI–26–DIAGNOSTICS ENGINE
190Author: Date:
2000 MR2 (RM760U)
Replace mass air flow meter.
5 Check continuity between terminal EVG of ECM connector and body ground.
PREPARATION:Disconnect the ECM with connector from body panel (See pageSF–62).CHECK:Check the continuity between terminal EVG of the ECM con-nector and body ground.OK:
Continuity (1 Ω or less)
NG Check and replace ECM (See page IN–28).
OK
6 Check for open in harness and connector between mass air flow meter and ECM(See page IN–28).
NG Repair or replace harness or connector.
OK
Replace mass air flow meter.
–DIAGNOSTICS ENGINEDI–27
191Author: Date:
2000 MR2 (RM760U)
DTC P0101 Mass Air Flow Circuit Range/PerformanceProblem
CIRCUIT DESCRIPTIONRefer to DTC P0100 on page DI–23.
DTC No. DTC Detection Condition Trouble Area
P0101
Conditions (a) and (b) continue 10 sec. or more with
engine speed 900 rpm or less: (2 trip detection logic)
(a) Throttle valve fully closed
(b) Mass air flow meter output 2.2 VM i fl tP0101
Conditions (a) and (b) continue 10 sec. or more with engine
speed 1,500 rpm or more: (2 trip detection logic)
(a) VTA 0.63 V
(b) Mass air flow meter output 1.06 V
Mass air flow meter
INSPECTION PROCEDUREHINT:Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze frame recordsthe engine conditions when the malfunction is detected. When troubleshooting, it is useful for determiningwhether the vehicle was running or stopped, the engine was warmed up or not, the air–fuel ratio was leanor rich, etc. at the time of the malfunction.
1 Are there any other codes (besides DTC P0101) being output?
NO Replace mass air flow meter.
YES
Go to relevant DTC chart (See page DI–14).
DI09C–08
FI4741
Fig. 1
Acceptable
Res
ista
nce
kΩ
– 20 0 20 40 60 80 100(– 4) 32 68 104 140 176 212
30
20
10
5
3
2
1
0.5
0.3
0.2
0.1
Temp.°C (F°)
DI–28–DIAGNOSTICS ENGINE
192Author: Date:
2000 MR2 (RM760U)
DTC P0110 Intake Air Temp. Circuit Malfunction
CIRCUIT DESCRIPTION
The intake air temperature sensor is built into the mass air flowmeter (see page DI–23) and senses the intake air temperature.A thermistor built in the sensor changes the resistance valueaccording to the intake air temperature, the lower the intake airtemperature, the greater the thermistor resistance value, andthe higher the intake air temperature, the lower the thermistorresistance value (See Fig. 1).The air intake temperature sensor is connected to the ECM(See below). The 5 V power source voltage in the ECM is ap-plied to the intake air temperature sensor from the terminal THAvia a resistor R.That is, the resistor R and the intake air temp. sensor are con-nected in series. When the resistance value of the intake airtemp. sensor changes in accordance with changes in the intakeair temperature, the potential at terminal THA also changes.Based on this signal, the ECM increases the fuel injection vol-ume to improve driveability during cold engine operation.
DTC No. DTC Detection Condition Trouble Area
P0110 Open or short in intake air temp. sensor circuit
Open or short in intake air temp. sensor circuit
Intake air temp. sensor (built into mass air flow meter)
ECM
HINT:After confirming DTC P0110, use the OBD II scan tool or TOYOTA hand–held tester to confirm the intakeair temperature from the CURRENT DATA.
Temperature Displayed Malfunction
–40°C (–40°F) Open circuit
140°C (284°F) or more Short circuit
DI37Z–03
A10940
(Built into M1 Mass Air Flow Meter)
4
5
Intake Air Temp. Sensor
Y–B
BRE418
E4
22THA
E2
E1
R
5 V
ECM
THA
E2
–DIAGNOSTICS ENGINEDI–29
193Author: Date:
2000 MR2 (RM760U)
WIRING DIAGRAM
INSPECTION PROCEDUREHINT: If DTCs P100, P0101, P0110, P0115 and P0120 are output simultaneously, E2 (sensor ground) may
be open. Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze frame
records the engine conditions when the malfunction is detected. When troubleshooting, it is useful fordetermining whether the vehicle was running or stopped, the engine was warmed up or not, the air–fuelratio was lean or rich, etc. at the time of the malfunction.
1 Connect OBD II scan tool or TOYOTA hand–held tester, and read value of intakeair temperature.
PREPARATION:(a) Connect the OBD II scan tool or TOYOTA hand–held tester to the DLC3.(b) Turn the ignition switch ON and push the OBD II scan tool or TOYOTA hand–held tester main switch
ON.CHECK:Read the temperature value on the OBD II scan tool or TOYOTA hand–held tester.OK:
Same as actual air intake temperature.HINT: If there is open circuit, OBD II scan tool or TOYOTA hand–held tester indicates –40°C (–40°F).
If there is short circuit, OBD II scan tool or TOYOTA hand-held tester indicates 140°C (284°F) or more.
NG –40°C (–40°F) ....Go to step 2. 140°C (284°F) or more ....Go to step 4.
OK
A12232BE6653
A12237
ECM
1
222
18
Intake Air Temp.Sensor
E4
5 V
E4THA
E2
E1
ON
BE6653
A11494A12233
A12724
Intake Air Temp.Sensor
ECM
22
18E4
E4 THA
E2
5 V
E1
THA E2
ON
DI–30–DIAGNOSTICS ENGINE
194Author: Date:
2000 MR2 (RM760U)
Check for intermittent problems(See page DI–3).
2 Check for open in harness or ECM.
PREPARATION:(a) Disconnect the mass air flow meter connector.(b) Connect the sensor wire harness terminals together.(c) Turn the ignition switch ON.CHECK:Read the temperature value on the OBD II scan tool or TOYO-TA hand–held tester.OK:
Temperature value: 140 °C (284°F) or more
OK Confirm good connection at sensor. If OK,replace mass air flow meter.
NG
3 Check for open in harness or ECM.
PREPARATION:(a) Disconnect the ECM with connector from body panel
(See page SF–62).(b) Connect between terminals THA and E2 of the ECM con-
nector.HINT:The mass air flow meter connector is disconnected. Beforechecking, do a visual and contact pressure check for the ECMconnector (See page IN–28).(c) Turn the ignition switch ON.CHECK:Read the temperature value on the OBD II scan tool or TOYO-TA hand–held tester.OK:
Temperature value: 140 °C (284°F) or more
OK Open in harness between terminals E2 or THA,repair or replace harness.
NG
A12234BE6653
A12238
ON
Intake Air Temp.Sensor
2
1
ECM
22
18
THA
E2E1
5 V
E4
E4
BE6653
A09341A12235
A12726
Intake Air Temp.Sensor
ECM
THA
E2
5 V
E1
ON
E4 Connector
–DIAGNOSTICS ENGINEDI–31
195Author: Date:
2000 MR2 (RM760U)
Confirm good connection at ECM. If OK,check and replace ECM (See page IN–28).
4 Check for short in harness and ECM.
PREPARATION:(a) Disconnect the mass air flow meter connector.(b) Turn the ignition switch ON.CHECK:Read the temperature value on the OBD II scan tool or TOYO-TA hand–held tester.OK:
Temperature value: –40 °C (–40°F)
OK Replace mass air flow meter.
NG
5 Check for short in harness or ECM.
PREPARATION:(a) Disconnect the ECM with connector from body panel
(See page SF–62).(b) Disconnect the E4 connector from the ECM.HINT:The mass air flow meter connector is disconnected.(c) Turn the ignition switch ON.CHECK:Read the temperature value on the OBD II scan tool or TOYO-TA hand–held tester.OK:
Temperature value: –40 °C (–40°F)
OK Repair or replace harness or connector.
NG
Check and replace ECM (See page IN–28).
A10940
E1Engine Coolant Temp.Sensor
2
1
ECM
R–L
BR
14
E4
E4
18
5 V
THW
E2
E1
RTHW
E2
DI–32–DIAGNOSTICS ENGINE
196Author: Date:
2000 MR2 (RM760U)
DTC P0115 Engine Coolant Temp. Circuit Malfunction
CIRCUIT DESCRIPTIONA thermistor built into the engine coolant temperature sensor changes the resistance value according to theengine coolant temperature.The structure of the sensor and connection to the ECM is the same as in the intake air temperature circuitmalfunction shown on page DI–28.
DTC No. DTC Detection Condition Trouble Area
P0115Open or short in engine coolant temp. sensor circuit for 0.5
sec.
Open or short in engine coolant temp. sensor circuit
Engine coolant temp. sensor
ECM
HINT:After confirming DTC P0115, use the OBD II scan tool or TOYOTA hand–held tester to confirm the enginecoolant temperature from the CURRENT DATA.
Temp. Displayed Malfunction
–40°C (–40°F) Open circuit
140°C (284°F) or more Short circuit
WIRING DIAGRAM
INSPECTION PROCEDUREHINT: If DTCs P0100, P0101, P0110, P0115 and P0120 are output simultaneously, E2 (sensor ground) may
be open. Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze frame
records the engine conditions when the malfunction is detected. When troubleshooting, it is useful fordetermining whether the vehicle was running or stopped, the engine was warmed up or not, the air–fuelratio was lean or rich, etc. at the time of the malfunction.
DI380–03
A12232BE6653
A12237
ECM
ON
Engine CoolantTemp. Sensor
2
1
14
18
THW
E2
5 V
E1
E4
E4
–DIAGNOSTICS ENGINEDI–33
197Author: Date:
2000 MR2 (RM760U)
1 Connect OBD II scan tool or TOYOTA hand–held tester, and read value of engine coolant temperature.
PREPARATION:(a) Connect the OBD II scan tool or TOYOTA hand–held tester to the DLC3.(b) Turn the ignition switch ON and push the OBD II scan tool or TOYOTA hand–held tester main switch
ON.CHECK:Read the temperature value on the OBD II scan tool or TOYOTA hand–held tester.OK:
Same as actual engine coolant temperature.HINT: If there is open circuit, OBD II scan tool or TOYOTA hand–held tester indicates –40°C (–40°F).
If there is open circuit, OBD II scan tool or TOYOTA hand-held tester indicates 140°C (284°F) or more.
NG –40°C (–40°F) ... Go to step 2.140°C (284°F) or more ... Go to step 4.
OK
Check for intermittent problems(See page DI–3).
2 Check for open in harness or ECM.
PREPARATION:(a) Disconnect the engine coolant temperature sensor con-
nector.(b) Connect the sensor wire harness terminals together.(c) Turn the ignition switch ON.CHECK:Read the temperature value on the OBD II scan tool or TOYO-TA hand–held tester.OK:
Temperature value: 140 °C (284°F) or more
OK Confirm good connection at sensor. If OK, replace engine coolant temperature sensor.
NG
BE6653
A11496A12233
A12728
ON
14
Engine CoolantTemp. Sensor
2
1
ECM
THW E2
18
5V
THW
E2E1
E4
E4
A12234BE6653
A12238
ON
Engine CoolantTemp. Sensor
14
18
ECM
E4
E4
THW
E2
5 V
E1
DI–34–DIAGNOSTICS ENGINE
198Author: Date:
2000 MR2 (RM760U)
3 Check for open in harness or ECM.
PREPARATION:(a) Disconnect the ECM with connector from body panel
(See page SF–62).(b) Connect between terminals THW and E2 of the ECM con-
nector.HINT:The engine coolant temperature sensor connector is discon-nected. Before checking, do a visual and contact pressurecheck for the ECM connector (See page IN–28).(c) Turn the ignition switch ON.CHECK:Read the temperature value on the OBD II scan tool or TOYO-TA hand–held tester.OK:
Temperature value: 140 °C (284°F) or more
OK Open in harness between terminals E2 or THW,repair or replace harness.
NG
Confirm good connection at ECM. If OK,check and replace ECM (See page IN–28).
4 Check for short in harness and ECM.
PREPARATION:(a) Disconnect the engine coolant temperature sensor con-
nector.(b) Turn the ignition switch ON.CHECK:Read the temperature value on the OBD II scan tool or TOYO-TA hand–held tester.OK:
Temperature value: – 40 °C (– 40°F)
OK Replace engine coolant temperature sensor.
NG
BE6653
A09341A12235
A12726
Intake Air Temp.Sensor
ECM
THA
E2
5 V
E1
ON
E4 Connector
–DIAGNOSTICS ENGINEDI–35
199Author: Date:
2000 MR2 (RM760U)
5 Check for short in harness or ECM.
PREPARATION:(a) Disconnect the ECM with connector from body panel
(See page SF–62).(b) Disconnect the E4 connector from the ECM.HINT:The engine coolant temperature sensor connector is discon-nected.(c) Turn the ignition switch ON.CHECK:Read the temperature value on the OBD II scan tool or TOYO-TA hand–held tester.OK:
Temperature value: –40 °C (–40°F)
OK Repair or replace harness or connector.
NG
Check and replace ECM (See page IN–28).
DI–36–DIAGNOSTICS ENGINE
200Author: Date:
2000 MR2 (RM760U)
DTC P0116 Engine Coolant Temp. Circuit Range/Performance Problem
CIRCUIT DESCRIPTIONRefer to DTC P0115 on page DI–32.
DTC No. DTC Detection Condition Trouble Area
When engine starts, water temp. is –7°C (20°F) or less. And,
20 min. or more after engine starts, engine coolant temp. sen-
sor value is 20°C (68°F) or less (2 trip detection logic)C li t
P0116 When engine starts, water temp. is between –7°C (20°F) and
10°C (50°F)
And, 5 min. or more after engine starts, engine coolant temp.
sensor value is 20°C (68°F) or less (2 trip detection logic)
Cooling system
Engine coolant temp. sensor
INSPECTION PROCEDUREHINT: If DTCs P0115 and P0116 are output simultaneously, engine coolant temperature sensor circuit may
be open. Perform troubleshooting of DTC P0115 first. Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze frame
records the engine conditions when the malfunction is detected. When troubleshooting, it is useful fordetermining whether the vehicle was running or stopped, the engine was warmed up or not, the air–fuelratio was lean or rich, etc. at the time of the malfunction.
1 Are there any other codes (besides DTC P0116) being output?
YES Go to relevant DTC chart (See page DI–14).
NO
2 Check thermostat (See page CO–10).
NG Replace thermostat.
OK
Replace engine coolant temperature sensor.
DI381–03
P24296
Throttle PositionSensor
VCVTA
E2
ECM
A12544
T1 Throttle Position Sensor
3
1
2
L–R
Y–G
BRE418
23
2 VC
VTA
E2
E1
5 V
ECM
E4
E4VC
VTA
E2
–DIAGNOSTICS ENGINEDI–37
201Author: Date:
2000 MR2 (RM760U)
DTC P0120 Throttle/Pedal Position Sensor/Switch ”A”Circuit Malfunction
CIRCUIT DESCRIPTIONThe throttle position sensor is mounted in the throttle body anddetects the throttle valve opening angle. When the throttle valveis fully closed, a voltage of approximately 0.3 – 0.8 V is appliedto terminal VTA of the ECM. The voltage applied to the termi-nals VTA of the ECM increases in proportion to the openingangle of the throttle valve and becomes approximately 3.2 – 4.9V when the throttle valve is fully opened. The ECM judges thevehicle driving conditions from this signal input from terminalVTA, and uses it as one of the conditions to decide the air–fuelratio correction, power increase correction and fuel–cut controletc.
DTC No. DTC Detection Condition Trouble Area
P0120
Condition (a) or (b) continues with more than 5 sec.:
(a) VTA < 0.1 V
(b) VTA > 4.9 V
Open or short in throttle position sensor circuit
Throttle position sensor
ECM
HINT:After confirming DTC P0120, use the OBD II scan tool or TOYOTA hand–held tester to confirm the throttlevalve opening percentage.
Throttle valve opening position expressed as percentageT bl A
Throttle valve fully closed Throttle valve fully openTrouble Area
0 % 0 %VC circuit open
VTA lcircuit open or short
Approx. 100 % Approx. 100 % E2 circuit open
WIRING DIAGRAM
DI382–05
FI7052
BE6653
S05338 A05445
ON 1
(+)
(–)
DI–38–DIAGNOSTICS ENGINE
202Author: Date:
2000 MR2 (RM760U)
INSPECTION PROCEDURE
HINT: If DTCs P0100, P0106, P0110, P0115 and P0120 are output simultaneously, E2 (sensor ground) may
be open. Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze frame
records the engine conditions when the malfunction is detected. When troubleshooting, it is useful fordetermining whether the vehicle was running or stopped, the engine was warmed up or not, the air–fuelratio was lean or rich, etc. at the time of the malfunction.
1 Connect OBD II scan tool or TOYOTA hand–held tester, read throttle valve open-ing percentage.
PREPARATION:(a) Connect the OBD II scan tool or TOYOTA hand–held tes-
ter to the DLC3.(b) Turn the ignition switch ON and push the OBD II scan tool
or TOYOTA hand–held tester main switch ON.CHECK:Read the throttle valve opening percentage.OK:
Throttle valveThrottle valve opening position
expressed as percentage
Fully open Approx. 70 %
Fully closed Approx. 10 %
OK Check for intermittent problems(See page DI–3).
NG
2 Check voltage between terminal 1 of throttle position sensor connector andbody ground.
PREPARATION:(a) Disconnect the throttle position sensor connector.(b) Turn the ignition switch ON.CHECK:Measure the voltage between terminal 1 of the throttle positionconnector and body ground.OK:
Voltage: 4.5 – 5.5 V
NG Go to step 5.
P24611
A11498 A12730
ON
(+) (–)
E2VTA
A09347
BE6653
A12731
ON
VC E2
(+) (–)
–DIAGNOSTICS ENGINEDI–39
203Author: Date:
2000 MR2 (RM760U)
OK
3 Check throttle position sensor (See page SF–33).
NG Replace throttle position sensor.
OK
4 Check voltage between terminals VTA and E2 of ECM connector.
PREPARATION:(a) Disconnect the ECM with connector from body panel
(See page SF–62).(b) Turn the ignition switch ON.CHECK:Measure the voltage between terminals VTA and E2 of the ECMconnector.OK:
Throttle valve Voltage
Fully closed 0.3 – 1.0 V
Fully open 3.2 – 4.9 V
OK Check and replace ECM (See page IN–28).
NG
Check for open and short in harness and connector in VTA or E2 circuit between ECM and throttleposition sensor (See page IN–28).
5 Check voltage between terminals VC and E2 of ECM connector.
PREPARATION:(a) Disconnect the ECM with connector from body panel
(See page SF–62).(b) Turn the ignition switch ON.CHECK:Measure the voltage between terminals VC and E2 of the ECMconnector.
DI–40–DIAGNOSTICS ENGINE
204Author: Date:
2000 MR2 (RM760U)
OK:Voltage: 4.5 – 5.5 V
NG Check and replace ECM (See page IN–28).
OK
Check for open in harness and connector inVC circuit between ECM and sensor (Seepage IN–28).
–DIAGNOSTICS ENGINEDI–41
205Author: Date:
2000 MR2 (RM760U)
DTC P0121 Throttle/Pedal Position/Switch ”A” SensorCircuit Range/Performance Problem
CIRCUIT DESCRIPTIONRefer to DTC P0120 on page DI–37.
DTC No. DTC Detection Condition Trouble Area
P0121
After vehicle speed has been exceeded 30 km/h (19 mph)
even once, output value of throttle position sensor is out of
applicable range for vehicle speed is more than 0 km/h (0
mph). (2 trip detection logic)
Throttle position sensor
INSPECTION PROCEDUREHINT:Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze frame recordsthe engine conditions when the malfunction is detected. When troubleshooting, it is useful for determiningwhether the vehicle was running or stopped, the engine was warmed up or not, the air–fuel ratio was leanor rich, etc. at the time of the malfunction.
1 Are there any other codes (besides DTC P0121) being output?
YES Go to relevant DTC chart (See page DI–14).
NO
Replace throttle position sensor.
DI383–03
P21242 FI7210A04485
Atmosphere
Flange
Platinum Electrode
Solid Electrolyte(Zirconia Element)Platinum ElectrodeHeaterCoating (Ceramic)
Exhaust Gas
Cover
Ideal Air–Fuel Mixture
Out
put
Vol
tage
Richer – Air Fuel Ratio – Leaner
DI–42–DIAGNOSTICS ENGINE
206Author: Date:
2000 MR2 (RM760U)
DTC P0125 Insufficient Coolant Temp. for Closed LoopFuel Control
CIRCUIT DESCRIPTIONTo obtain a high purification rate for the CO, HC and NOx components of the exhaust gas, a three–way cata-lytic converter is used, but for the most efficient use of the three–way catalytic converter, the air–fuel ratiomust be precisely controlled so that it is always close to the stoichiometric air–fuel ratio.The heated oxygen sensor (bank 1, 2 sensor 1) has the characteristic and that output voltage, whichchanges suddenly in the vicinity of the stoichiometric air–fuel ratio. This is used to detect the oxygen con-centration in the exhaust gas and provide the ECM with feedback to control the air–fuel ratio.When the air–fuel ratio becomes LEAN, the oxygen concentration in the exhaust increases and the heatedoxygen sensor informs the ECM of the LEAN condition (small electromotive force: < 0.45 V).When the air–fuel ratio is RICHER than the stoichiometric air–fuel ratio the oxygen concentration in the ex-haust gas in reduced and the heated oxygen sensor informs the ECM of the RICH condition (large electro-motive force: > 0.45 V). The ECM judges by the electromotive force from the heated oxygen sensor whether the air–fuel ratio is RICHor LEAN and controls the injection time accordingly. However, if malfunction of the heated oxygen sensorcauses output of abnormal electromotive force, the ECM is unable to perform accurate air–fuel ratio control.The heated oxygen sensors include a heater which heats the zirconia element. The heater is controlled bythe ECM. When the intake air volume is low (the temp. of the exhaust gas is low) current flows to the heaterto heat the sensor for accurate oxygen concentration detection.
DTC No. DTC Detection Condition Trouble Area
P0125
After engine is warmed up, oxygen sensor (bank 1, 2 sensor 1)
output does not indicate RICH ( 0.45 V) even once when
conditions (a), (b), and (c) continue for at least 1.5 min.:
(a) Engine speed: 1,400 rpm or more
(b) Vehicle speed: 40 – 100 km/h (25 – 62 mph)
(c) Throttle valve does not fully closed
Open or short in heated oxygen sensor (bank 1, 2 sensor 1)
circuit
Heated oxygen sensor (bank 1, 2 sensor 1)
Air induction system
Fuel system
Injector
Gas leakage on exhaust system
ECM
DI384–04
A13045
ECM
B
B–Y
L–B
B–W
BR
12
4
12
3
9
8
21
5
6
B–R
EB
H1Heated Oxygen Sensor(Bank 1 Sensor 1)
FromTerminal 3 ofEFI MAIN Relay(See page DI–132)
H2Heated Oxygen Sensor(Bank 1 Sensor 2)
H3Heated Oxygen Sensor(Bank 2 Sensor 1)
OX1A
HT1A
OX1B
HT1B
OX2A
HT2A
E1
E4
E4
E4
E4
E4
E4
E4
B
B
BR
B–R
BR
B–R
B–R
B–R
3
12
4 3
12
4 3
BR
BR
BR
BC1
5
B–R
1
EFI22
1
1
B
FL Block
–DIAGNOSTICS ENGINEDI–43
207Author: Date:
2000 MR2 (RM760U)
HINT:After confirming DTC P0125, use the OBD II scan tool or TOYOTA hand-held tester to confirm voltage outputof the heated oxygen sensor (bank 1, 2 sensor 1) from the CURRENT DATA.
If the voltage output of the heated oxygen sensor (bank 1, 2 sensor 1) is less than 0.1 V, the heated oxygen
sensor circuit may be open or short.
WIRING DIAGRAM
INSPECTION PROCEDUREHINT: If the vehicle runs out of fuel, the air–fuel ratio is LEAN and DTC P0125 will be recorded. The MIL then
comes on. Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze frame
records the engine conditions when the malfunction is detected. When troubleshooting, it is useful fordetermining whether the vehicle was running or stopped, the engine was warmed up or not, the air–fuelratio was lean or rich, etc. at the time of the malfunction.
1 Are there any other codes (besides DTC P0125) being output ?
YES Go to relevant DTC chart (See page DI–14).
NO
DI–44–DIAGNOSTICS ENGINE
208Author: Date:
2000 MR2 (RM760U)
2 Connect OBD II scan tool or TOYOTA hand–held tester and read value for volt-age output of heated oxygen sensor (bank 1, 2 sensor 1).
PREPARATION:(a) Connect the OBD II scan tool or TOYOTA hand–held tester to the DLC3.(b) Warm up the engine to normal operating temperature (above 75°C).CHECK:Read the voltage output of the heated oxygen sensor when the engine is suddenly raced.HINT:Perform quick racing to 4,000 rpm for 3 times using the accelerator pedal.OK:
Heated oxygen sensor outputs a RICH signal (0.45 V or more) at least once.
OK Go to step 9.
NG
3 Check for open and short in harness and connector between ECM and heatedoxygen sensor (bank 1, 2 sensor 1) (See page IN–28).
NG Repair or replace harness or connector.
OK
4 Check whether misfire has occurred or not by monitoring DTC and data list.
NG Perform troubleshooting for misfire (See pageDI–63).
OK
5 Check air induction system (See page SF–1).
NG Repair or replace induction system.
OK
–DIAGNOSTICS ENGINEDI–45
209Author: Date:
2000 MR2 (RM760U)
6 Check fuel pressure (See page SF–7).
NG Check and repair fuel pump, fuel pipe line andfilter .
OK
7 Check injector injection (See page SF–24).
NG Replace injector.
OK
8 Check gas leakage on exhaust system.
NG Repair or replace.
OK
Replace heated oxygen sensor (bank 1, 2sensor 1).
9 Perform confirmation driving pattern (See page DI–47).
Go
10 Is there DTC P0125 being output again?
YES Check and replace ECM (See page IN–18).
NO
DI–46–DIAGNOSTICS ENGINE
210Author: Date:
2000 MR2 (RM760U)
11 Did vehicle runs out of fuel in past?
NO Check for intermittent problems (See page DI–3).
YES
DTC P0125 is caused by shortage of fuel.
A09299
Vehicle speed
40 km/h(24 mph)
IdlingIG SW OFF
(a) (b)
(c)
(d)
(e)
(d) (d)
(e) (f)
100 sec.or more
20 sec.or more
20 sec.or more 30 sec.
20 sec.or more
20 sec.or more
20 sec.or more
–DIAGNOSTICS ENGINEDI–47
211Author: Date:
2000 MR2 (RM760U)
DTC P0130 Oxygen Sensor Circuit Malfunction (Bank 1Sensor 1)
DTC P0150 Oxygen Sensor Circuit Malfunction (Bank 2Sensor 1)
CIRCUIT DESCRIPTIONRefer to DTC P0125 on page DI–42.
DTC No. DTC Detection Condition Trouble Area
P0130
P0150
Voltage output of heated oxygen sensor remains at 0.4 V or
more, or 0.55 V or less, during idling after engine is warmed up
(2 trip detection logic)
Open or short in heated oxygen sensor circuit
Heated oxygen sensor
Air induction system
Fuel pressure
Injector
ECM
HINT: Bank 1 refers to the bank that includes the cylinder No. 1.
Bank 2 refers to the bank that excludes the cylinder No. 1.
Sensor 1 refers to the sensor closer to the engine body.
The heated oxygen sensor's output voltage and the short-term fuel trim value can be read using the
OBD II scan tool or TOYOTA hand-held tester.
WIRING DIAGRAMRefer to DTC P0125 on page DI–42.
CONFIRMATION DRIVING PATTERN
(a) Connect the TOYOTA hand–held tester to the DLC3.(b) Switch the TOYOTA hand–held tester from the normal mode to the check mode (See page DI–3).(c) Start the engine and let the engine idle for 100 sec. or more.(d) Drive the vehicle at 40 km/h (24 mph) or more for 20 sec. or more.(e) Let the engine idle for 20 sec. or more.
DI385–04
P18349
DI–48–DIAGNOSTICS ENGINE
212Author: Date:
2000 MR2 (RM760U)
(f) Let the engine idle for 30 sec.HINT:If a malfunction exists, the MIL will light up during step (f).NOTICE:If the conditions in this test are not strictly followed, detection of the malfunction will not be possible.If you do not have a TOYOTA hand–held tester, turn the ignition switch OFF after performing steps(c) to (f), then perform steps (c) to (f) again.
INSPECTION PROCEDUREHINT:Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze frame recordsthe engine conditions when the malfunction is detected. When troubleshooting, it is useful for determiningwhether the vehicle was running or stopped, the engine was warmed up or not, the air–fuel ratio was leanor rich, etc. at the time of the malfunction.
1 Are there any other codes (besides DTC P0130 or P0150) being output?
YES Go to relevant DTC chart (See page DI–14).
NO
2 Check output voltage of heated oxygen sensor during idling.
PREPARATION:Keep the engine at 2,500 rpm for approx. 90 sec. to warm up the heated oxygen sensor.CHECK:Use the OBD II scan tool or TOYOTA hand–held tester to read the output voltage of the heated oxygen sen-sor during idling.OK:
Heated oxygen sensor output voltage:Alternates repeatedly between less than 0.4 V and more than 0.55 V (See the following table).
OK Perform confirmation driving pattern(See page DI–47).
–DIAGNOSTICS ENGINEDI–49
213Author: Date:
2000 MR2 (RM760U)
NG
3 Check for open and short in harness and connector between ECM and heatedoxygen sensor (See page IN–18).
NG Repair or replace harness or connector.
OK
4 Check air induction system (See page SF–1).
NG Repair or replace induction system.
OK
5 Check fuel pressure (See page SF–7).
NG Check and repair fuel pump, fuel pipe line andfilter.
OK
6 Check injector injection (See page SF–24).
NG Replace injector.
OK
Replace heated oxygen sensor.
DI–50–DIAGNOSTICS ENGINE
214Author: Date:
2000 MR2 (RM760U)
7 Perform confirmation driving pattern (See page DI–47).
Go
8 Is there DTC P0130 or P0150 being output again?
YES Check for intermittent problems(See page DI–3).
NO
Check and replace ECM (See page IN–28).
–DIAGNOSTICS ENGINEDI–51
215Author: Date:
2000 MR2 (RM760U)
DTC P0133 Oxygen Sensor Circuit Slow Response(Bank 1 Sensor 1)
DTC P0153 Oxygen Sensor Circuit Slow Response(Bank 2 Sensor 1)
CIRCUIT DESCRIPTIONRefer to DTC P0125 on page DI–42.
DTC No. DTC Detection Condition Trouble Area
P0133
P0153
Response time for heated oxygen sensor’s voltage output to
change from rich to lean, or from lean to rich, is 1 sec. or more
during idling after engine is warmed up (2 trip detection logic)
Open or short in heated oxygen sensor circuit
Heated oxygen sensor
Air induction system
Fuel pressure
Injector
ECM
HINT: Sensor 1 refers to the sensor closer to the engine body.
Bank 1 refers to the bank that includes the cylinder No. 1.
Bank 2 refers to the bank that excludes the cylinder No. 1.
WIRING DIAGRAMRefer to DTC P0125 on page DI–42.
INSPECTION PROCEDUREHINT:Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze frame recordsthe engine conditions when the malfunction is detected. When troubleshooting, it is useful for determiningwhether the vehicle was running or stopped, the engine was warmed up or not, the air–fuel ratio was leanor rich, etc. at the time of the malfunction.
1 Are there any other codes (besides DTC P0133 or P0153) being output?
YES Go to relevant DTC chart (See page DI–14).
NO
DI5CW–03
P18349
DI–52–DIAGNOSTICS ENGINE
216Author: Date:
2000 MR2 (RM760U)
2 Check output voltage of heated oxygen sensor during idling.
PREPARATION:Keep the engine at 2,500 rpm for approx. 90 sec. to warm up the heated oxygen sensor.CHECK:Use the OBD II scan tool or TOYOTA hand–held tester to read the output voltage of the heated oxygen sen-sor during idling.OK:
Heated oxygen sensor output voltage:Alternates repeatedly between less than 0.4 V and more than 0.55 V (See the following table).
OK Perform confirmation driving pattern(See page DI–47).
NG
3 Check for open and short in harness and connector between ECM and heatedoxygen sensor (See page IN–18).
NG Repair or replace harness or connector.
OK
4 Check air induction system (See page SF–1).
NG Repair or replace induction system.
OK
–DIAGNOSTICS ENGINEDI–53
217Author: Date:
2000 MR2 (RM760U)
5 Check fuel pressure (See page SF–7).
NG Check and repair fuel pump, fuel pipe line andfilter (See page SF–1).
OK
6 Check injector injection (See page SF–24).
NG Replace injector.
OK
Replace heated oxygen sensor.
7 Perform confirmation driving pattern (See page DI–47).
Go
8 Is there DTC P0133 or P0153 being output again?
YES Check for intermittent problems(See page DI–3).
NO
Check and replace ECM (See page IN–28).
DI–54–DIAGNOSTICS ENGINE
218Author: Date:
2000 MR2 (RM760U)
DTC P0135 Oxygen Sensor Heater Circuit Malfunction(Bank 1 Sensor 1)
DTC P0141 Oxygen Sensor Heater Circuit Malfunction(Bank 1 Sensor 2)
DTC P0155 Oxygen Sensor Heater Circuit Malfunction(Bank 2 Sensor 1)
CIRCUIT DESCRIPTIONRefer to DTC P0125 on page DI–42.
DTC No. DTC Detection Condition Trouble Area
P0135
P0141
When heater operates, heater current exceeds 2 A (2 trip
detection logic) Open or short in heater circuit of heated oxygen sensor
H t d h tP0141
P0155Heater current of 0.2 A or less when heater operates (2 trip
detection logic)
Heated oxygen sensor heater
ECM
HINT: Bank 1 refers to the bank that includes cylinder No. 1. Bank 2 refers to the bank that excludes cylinder No. 1. Sensor 1 refers to the sensor closer to the engine body.
WIRING DIAGRAMRefer to DTC P0125 on page DI–42.
INSPECTION PROCEDUREHINT:Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze frame recordsthe engine conditions when the malfunction is detected. When troubleshooting, it is useful for determiningwhether the vehicle was running or stopped, the engine was warmed up or not, the air–fuel ratio was leanor rich, etc. at the time of the malfunction.
DI1ED–08
A12733
ONHT1A HT1BHT2A
(+) (–)
–DIAGNOSTICS ENGINEDI–55
219Author: Date:
2000 MR2 (RM760U)
1 Check voltage between terminals HT1A, HT1B and HT2A of ECM connector andbody ground.
PREPARATION:(a) Disconnect the ECM with connector from body panel
(See page SF–62).(b) Turn the ignition switch ON.CHECK:Measure the voltage between terminals HT1A, HT1B of theECM connector and body ground.HINT: Terminal HT1A connects to bank 1 sensor 1. Terminal HT1B connects to bank 2 sensor 1. Terminal HT2A connects to bank 1 sensor 2.
OK:Voltage: 9 – 14 V
OK Check and replace ECM (See page IN–28).
NG
2 Check resistance of heated oxygen sensor heater (See page SF–61).
NG Replace heated oxygen sensor.
OK
Repair or replace harness or connector between EFI main relay (Marking: EFI MAIN) and heatedoxygen sensor and heated oxygen sensor and ECM (See page IN–28).
A09300
Vehicle speed
40 km/h(24 mph)
Idling(c)
(d)
(e)
(a)
IG SW OFF
(b)
(e)
60 sec.or more
(d) (d)
Once40 sec.or more
Twice40 sec.or more
11 times40 sec.or more
10 sec. 10 sec.
(e)
10 sec.
DI–56–DIAGNOSTICS ENGINE
220Author: Date:
2000 MR2 (RM760U)
DTC P0136 Oxygen Sensor Circuit Malfunction (Bank 1Sensor 2)
CIRCUIT DESCRIPTIONRefer to DTC P0125 on page DI–42.
DTC No. DTC Detection Condition Trouble Area
P0136
Voltage output of heated oxygen sensor remains at 0.40 V or
more, or 0.5 V or less when vehicle is driven at 40 km/h (25
mph) or more after engine is warmed up (2 trip detection logic)
Open or short in heated oxygen sensor circuit
Heated oxygen sensor
HINT: Bank 1 refers to the bank that includes the cylinder No. 1
Sensor 2 refers to the sensor farther away from the engine body.
WIRING DIAGRAMRefer to DTC P0125 on page DI–42.
CONFIRMATION DRIVING PATTERN
(a) Connect the hand–held tester to the DLC3.(b) Switch the hand–held tester from the normal mode to the check (test) mode (See page DI–3).(c) Start the engine and let the engine idle for 60 seconds or more.(d) Drive the vehicle at 40 km/h (24 mph) or more for 40 seconds or more.(e) Let the engine idle for 10 seconds or more.(f) Preform steps (d) to (e) 9 times.HINT:If a malfunction exists, the MIL will be indicated on the multi information display during step (f).NOTICE:If the conditions in this test are not strictly followed, detection of the malfunction will not be possible.If you do not have a hand–held tester, turn the ignition switch OFF after performing steps from (c)to (f), then perform steps from (c) to (f) again.
DI6OR–02
–DIAGNOSTICS ENGINEDI–57
221Author: Date:
2000 MR2 (RM760U)
INSPECTION PROCEDUREHINT:Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze frame recordsthe engine conditions when the malfunction is detected. When troubleshooting, it is useful for determiningwhether the vehicle was running or stopped, the engine was warmed up or not, the air–fuel ratio was leanor rich, etc. at the time of the malfunction.
1 Are there any other codes (besides DTC P0136) being output?
YES Go to relevant DTC chart (See page DI–14).
NO
2 Check for open and short in harness and connector between ECM and heatedoxygen sensor (See page IN–28).
NG Repair or replace harness or connector.
OK
3 Check output voltage of heated oxygen sensor.
PREPARATION:(a) Connect the OBD II scan tool or TOYOTA hand–held tester to the DLC3.(b) Warm up the engine to normal temperature of the operating.CHECK:Read the voltage output of the heated oxygen sensor when the engine is suddenly raced.HINT:Perform quick racing to 4,000 rpm for 3 min. using the accelerator pedal.OK:
Heated oxygen sensor output voltage: Alternates from 0.40 V or less to 0.5 V or more.
OK Check that each connector is properly con-nected.
NG
Replace heated oxygen sensor.
DI–58–DIAGNOSTICS ENGINE
222Author: Date:
2000 MR2 (RM760U)
DTC P0171 System too Lean (Fuel Trim) (Bank 1)
DTC P0172 System too Rich (Fuel Trim) (Bank 1)
DTC P0174 System too Lean (Fuel Trim) (Bank 2)
DTC P0175 System too Rich (Fuel Trim) (Bank 2)
CIRCUIT DESCRIPTIONFuel trim refers to the feedback compensation value compared to the basic injection time. Fuel trim includesshort–term fuel trim and long–term fuel trim.Short–term fuel trim is the short–term fuel compensation used to maintain the air–fuel ratio at its idealtheoretical value. The signal from the heated oxygen sensor indicates whether the air–fuel ratio is RICH orLEAN compared to the ideal theoretical value, triggering a reduction in fuel volume if the air–fuel ratio is rich,and an increase in fuel volume if it is lean.Long–term fuel trim is overall fuel compensation carried out long–term to compensate for continual deviationof the short–term fuel trim from the central value due to individual engine differences, wear overtime andchanges in the usage environment.If both the short–term fuel trim and long–term fuel trim are LEAN or RICH beyond a certain value, it is de-tected as a malfunction and the MIL lights up.
DTC No. DTC Detection Condition Trouble Area
P0171
P0174
When air–fuel ratio feedback is stable after warming up engine,
fuel trim is considerably in error on RICH side (2 trip detection
logic)
Air induction system
Injector blockage
Mass air flow meter
Engine coolant temp. sensor
Fuel pressure
Gas leakage on exhaust system
Open or short in heated oxygen sensor (bank 1, 2 sensor 1)
circuit
Heated oxygen sensor (bank 1, 2 sensor 1)
P0172
P0175
When air–fuel ratio feedback is stable after warming up engine,
fuel trim is considerably in error on LEAN side. (2 trip detection
logic)
Injector leak, blockage
Mass air flow meter
Engine coolant temp. sensor
Ignition system
Fuel pressure
Gas leakage on exhaust system
Open or short in heated oxygen sensor (bank 1, 2 sensor 1)
circuit
Heated oxygen sensor (bank 1, 2 sensor 1)
DI5CX–03
–DIAGNOSTICS ENGINEDI–59
223Author: Date:
2000 MR2 (RM760U)
HINT: When the DTC P0171 or P0174 is recorded, the actual air–fuel ratio is on the LEAN side. When DTC
P0172 or P0175 is recorded, the actual air–fuel ratio is on the RICH side. If the vehicle runs out of fuel, the air–fuel ratio is LEAN and the DTC P0171 is recorded. The MIL then
comes on. If the total of the short–term fuel trim value and long–term fuel trim value is within ±38 %, the system
is functioning normally. The heated oxygen sensor (Bank 1, 2 Sensor 1) output voltage and the short–term fuel trim value can
be read using the OBD II scan tool or TOYOTA hand–held tester.
WIRING DIAGRAMRefer to DTC P0125 on page DI–42.
INSPECTION PROCEDUREHINT:Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze frame recordsthe engine conditions when the malfunction is detected. When troubleshooting, it is useful for determiningwhether the vehicle was running or stopped, the engine was warmed up or not, the air–fuel ratio was leanor rich, etc. at the time of the malfunction.
1 Check air induction system (See page SF–1).
NG Repair or replace.
OK
2 Check injector injection (See page SF–24).
NG Replace injector.
OK
3 Check engine coolant temperature sensor (See page SF–55) and mass air flowmeter (See page SF–32).
NG Repair or replace.
OK
P18349
DI–60–DIAGNOSTICS ENGINE
224Author: Date:
2000 MR2 (RM760U)
4 Check for spark and ignition (See page IG–1).
NG Repair or replace.
OK
5 Check fuel pressure (See page SF–7).
NG Check and repair fuel pump, pressure regulator,fuel pipe line and filter.
OK
6 Check gas leakage on exhaust system.
NG Repair or replace.
OK
7 Check output voltage of heated oxygen sensor (bank 1, 2 sensor 1) during id-ling.
PREPARATION:Keep the engine at 2,500 rpm for approx. 90 sec. to warm up the heated oxygen sensor.CHECK:Use the OBD II scan tool or TOYOTA hand–held tester to read the output voltage of the heated oxygen sen-sor during idling.OK:
Heated oxygen sensor output voltage:Alternates repeatedly between less than 0.4 V and more than 0.55 V (See the following table).
–DIAGNOSTICS ENGINEDI–61
225Author: Date:
2000 MR2 (RM760U)
OK Perform confirmation driving pattern (See pageDI–47).
NG
8 Check for open and short in harness and connector between ECM and heatedoxygen sensor (bank 1, 2 sensor 1) (See page IN–18).
NG Repair or replace harness or connector.
OK
Replace heated oxygen sensor.
9 Perform confirmation driving pattern (See page DI–47).
GO
10 Is there DTC P0171, P0172, P0174 or P0175 being output again?
YES Check and replace ECM (See page IN–28).
NO
11 Did vehicle run out of fuel in past?
NO Check for intermittent problems (See pageDI–3).
YES
DI–62–DIAGNOSTICS ENGINE
226Author: Date:
2000 MR2 (RM760U)
DTC P0171, P0172, P0174 or P0175 is causedby shortage of fuel.
–DIAGNOSTICS ENGINEDI–63
227Author: Date:
2000 MR2 (RM760U)
DTC P0300 Random/Multiple Cylinder Misfire Detected
DTC P0301 Cylinder 1 Misfire Detected
DTC P0302 Cylinder 2 Misfire Detected
DTC P0303 Cylinder 3 Misfire Detected
DTC P0304 Cylinder 4 Misfire Detected
CIRCUIT DESCRIPTIONMisfire: The ECM uses the crankshaft position sensor and camshaft position sensor to monitor changes inthe crankshaft rotation for each cylinder.The ECM counts the number of times from the engine speed change rate, indicating that misfire has oc-curred. And when the misfire rate equals or exceeds the count indicating that the engine condition has deteri-orated, the MIL lights up.If the misfire rate is high enough and the driving conditions causes catalyst overheating, the MIL blinks whenmisfiring occurs.
DTC No. DTC Detection Condition Trouble Area
P0300Misfiring of random cylinders is detected during any particular
200 or 1,000 revolutions
Open or short in engine wire
Connector connection
Vacuum hose connection
P0301
P0302
For any particular 200 revolutions of engine, misfiring is de-
tected which can cause catalyst overheating (This causes MIL
to blink)
Vacuum hose connection
Ignition system
Injector
Fuel pressure
Mass air flow meter
Engine coolant temp. sensorP0302
P0303
P0304For any particular 1,000 revolutions of engine, misfiring is de-
tected which causes a deterioration in emissions (2 trip detec-
tion logic)
Engine coolant tem . sensor
Compression pressure
Valve clearance
Valve timing
ECM
HINT:When the 2 or more codes for a misfiring cylinder are recorded repeatedly but no random misfire code isrecorded, it indicates that the misfires were detected and recorded at different times.
DI7DE–01
A12545
ECM
#10
#20
#30
#40
I7Injector No. 2
I8Injector No. 3
I9Injector No. 4
E5
E5
E5
E5
1
2
3
4
1
1
2
2
12
1
I6Injector No. 1
2B–W
B
L
W
B–R B–R
B–R
B–R
B–R
B–R
B–R
From Terminal 3 of IG2 Relay(See page DI–132)
BC2
10B–R
DI–64–DIAGNOSTICS ENGINE
228Author: Date:
2000 MR2 (RM760U)
WIRING DIAGRAM
CONFIRMATION DRIVING PATTERN(a) Connect the TOYOTA hand–held tester or OBD II scan tool to the DLC3.(b) Record the DTC and the freeze frame data.(c) Use the TOYOTA hand–held tester to set to the check mode (See page DI–3).(d) Drive the vehicle several times with the engine speed, load and its surrounding range shown with EN-
GINE SPD, CALC LOAD in the freeze frame data or MISFIRE RPM, MISFIRE LOAD in the data list.If you have no TOYOTA hand–held tester, turn the ignition switch OFF after the symptom is simulatedthe first time. Then repeat the simulation process again.
HINT:In order to memorize DTC of misfire, it is necessary to drive around MISFIRE RPM, MISFIRE LOAD in thedata list for the following period of time.
Engine Speed Time
Idling 5 minutes and 45 seconds or more
1000 rpm 4 minutes or more
2000 rpm 2 minutes and 30 seconds or more
3000 rpm 1 minute and 30 seconds or more
(e) Check whether there is misfire or not by monitoring DTC and the freeze frame data. After that, recordthem.
(f) Turn the ignition switch OFF and wait at least 5 seconds.
INSPECTION PROCEDUREHINT: If the DTC besides misfire is memorized simultaneously, first perform the troubleshooting for them. Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze frame
records the engine conditions when the malfunction is detected. When troubleshooting, it is useful fordetermining whether the vehicle was running or stopped, the engine was warmed up or not, the air–fuelratio was lean or rich, etc. at the time of the malfunction.
When the vehicle is brought to the workshop and the misfire is not occurred, misfire can be confirmedby reproducing the condition or freeze frame data. Also, after finishing the repair, confirm that thereis no misfire. (See the confirmation driving pattern)
A11507BE6653
A12735
#10#20
ON
#30#40
(+) (–)
–DIAGNOSTICS ENGINEDI–65
229Author: Date:
2000 MR2 (RM760U)
When either of SHORT FT #1, LONG FT #1, SHORT FT #2 or LONG FT #2 in the freeze frame datais besides the range of ±20%, there is a possibility that the air–fuel ratio is inclining either to ”rich”(–20% or less) or ”lean” (+20% or more).
When COOLANT TEMP in the freeze frame data is less than 80°C (176°F), there is a possibility ormisfire only during warming up.
In the case that misfire cannot be reproduced, this may be because of the driving with shortage of fuel,the use of improper fuel, a stain of ignition plug, and etc.
1 Check wire harness, connector and vacuum hose in engine room.
CHECK:(a) Check the connection conditions of the wire harness and connector.(b) Check the disconnection, piping and break in the vacuum hose.
NG Repair or replace, then confirm that there is nomisfire (See the confirmation driving pattern).
OK
2 Check spark plug and spark of misfiring cylinder (See page IG–1).
NG Replace or check ignition system (See page IG–1).
OK
3 Check voltage of ECM terminal for injector of faulty cylinder.
PREPARATION:(a) Disconnect the ECM with connector from body panel
(See page SF–62).(b) Turn the ignition switch ON.CHECK:Measure the voltage between applicable terminal of the ECMconnector and body ground.OK:
Voltage: 9 – 14 V
A12490
Injector Signal Waveform20V/Division
GND
50 m sec./Division (Idling)
GND
Injection duration1 msec./Division (Idling)
20V/Division
(Magnification)
DI–66–DIAGNOSTICS ENGINE
230Author: Date:
2000 MR2 (RM760U)
Reference: INSPECTION USING OSCILLOSCOPEINJECTOR SIGNAL WAVEFORMWith the engine idling, check the waveform between terminals #10 – #40 and E01 of the ECM connector.HINT:The correct waveforms are shown.
OK Go to step 5.
NG
4 Check resistance of injector of misfiring cylinder (See page SF–21).
NG Replace injector.
OK
Check for open and short in harness and con-nector between injector and ECM (See pageIN–28).
5 Check fuel pressure (See page SF–7).
NG Check and repair fuel pump, pressure regulator,fuel pipe line and filter.
–DIAGNOSTICS ENGINEDI–67
231Author: Date:
2000 MR2 (RM760U)
OK
6 Check injector injection (See page SF–24).
NG Replace injector.
OK
7 Check mass air flow meter (See page SF–31) and engine coolant temperaturesensor (See page SF–55).
NG Repair or replace.
OK
Check compression pressure (See pageEM–3), valve clearance (See page EM–4), andvalve timing (See page EM–17).
A11751
K1Knock Sensor
ECM
KNK127E5
1
EA1BW
E2
1
A12492
KNK1
DI–68–DIAGNOSTICS ENGINE
232Author: Date:
2000 MR2 (RM760U)
DTC P0325 Knock Sensor 1 Circuit Malfunction (Bank 1)
CIRCUIT DESCRIPTIONThe knock sensor is fitted to the cylinder block to detect engine knocking. This sensor contains a piezoelec-tric element which generates a voltage when it becomes deformed. This occurs when the cylinder block vi-brates due to knocking. If engine knocking occurs, ignition timing is retarded to suppress it.
DTC No. DTC Detection Condition Trouble Area
P0325No knock sensor signal to ECM with engine speed, 2,000 rpm
or more
Open or short in knock sensor circuit
Knock sensor (looseness)
ECM
HINT:If the ECM detects above diagnosis conditions, it operates the fail safe function in which the corrective retardangle value is set to the maximum value.
WIRING DIAGRAM
INSPECTION PROCEDUREHINT:Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze frame recordsthe engine conditions when the malfunction is detected. When troubleshooting, it is useful for determiningwhether the vehicle was running or stopped, the engine was warmed up or not, the air–fuel ratio was leanor rich, etc. at the time of the malfunction.
1 Check continuity between terminal KNK1 of ECM connector and body ground.
PREPARATION:(a) Disconnect the ECM with connector from body panel
(See page SF–62).(b) Disconnect the E5 connector from the ECM.CHECK:Measure the resistance between terminal KNK1 of the ECMconnector and body ground.
DI38A–04
A00406
KNK1 Signal Waveform0.5V/ Division
0V
0V
5 msec./Division
50 sec./Division
0.5V/ Division
–DIAGNOSTICS ENGINEDI–69
233Author: Date:
2000 MR2 (RM760U)
OK:Resistance: 1 M Ω or higher
Reference: INSPECTION USING OSCILLOSCOPE With the engine racing at 4,000 rpm, measure the wave-
form between terminal KNK1 of the ECM connector andbody ground.
HINT:The correct waveforms are as shown.
Spread the time on the horizontal axis, and confirm thatperiod of the wave is 80 µ sec. (Normal mode vibration fre-quency of knock sensor:12.5 kHz)
HINT:If normal mode vibration frequency is not 7.6 kHz the sensor ismalfunctioning.
OK Go to step 3.
NG
2 Check knock sensor (See page SF–59).
NG Replace knock sensor.
OK
3 Check for open and short in harness and connector between ECM and knocksensor (See page IN–28).
NG Repair or replace harness or connector.
OK
4 Is malfunction corrected when a good knock sensor is installed?
YES Replace knock sensor.
DI–70–DIAGNOSTICS ENGINE
234Author: Date:
2000 MR2 (RM760U)
NO
Check and replace ECM (See page IN–28).
A12484
ECM
NE+
G2
E4
E4
16
15
NE–E424
C3Crankshaft Position Sensor
Signal Rotor on Intake Camshaft
C1Camshaft Position Sensor
Crank AngleSensor Plate
W
2
W
B
1
B
2
1
B
–DIAGNOSTICS ENGINEDI–71
235Author: Date:
2000 MR2 (RM760U)
DTC P0335 Crankshaft Position Sensor ”A” CircuitMalfunction
CIRCUIT DESCRIPTIONCrankshaft position sensor (NE signal) consists of a magnet, iron core and pick up coil.The NE signal plate (crank angle sensor plate) has 34 teeth and is mounted on the crankshaft. The NE signalsensor generates 34 signals at every engine revolution. The ECM detects the standard crankshaft anglebased on the G signal, the actual crankshaft angle and the engine speed by the NE signal.
DTC No. DTC Detection Condition Trouble Area
P0335
No crankshaft position sensor signal to ECM during cranking
(2 trip detection logic)Open or short in crankshaft position sensor circuit
Crankshaft position sensorP0335
No crankshaft position sensor signal to ECM with engine
speed 600 rpm or more (2 trip detection logic)
Crankshaft osition sensor
Crank angle sensor plate
ECM
WIRING DIAGRAM
INSPECTION PROCEDUREHINT: Perform troubleshooting of DTC P0335 1st. If no trouble is found, troubleshoot the following mechani-
cal system. Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze frame
records the engine conditions when the malfunction is detected. When troubleshooting, it is useful fordetermining whether the vehicle was running or stopped, the engine was warmed up or not, the air–fuelratio was lean or rich, etc. at the time of the malfunction.
DI38B–03
A03961
G and NE Signal Waveforms
G
NE
5 V/Division
20 msec./Division (Idling)
DI–72–DIAGNOSTICS ENGINE
236Author: Date:
2000 MR2 (RM760U)
1 Check resistance of crankshaft position sensor (See page IG–1).
Reference: INSPECTION USING OSCILLOSCOPEDuring cranking or idling, check the waveform between termi-nals G2 and NE– and NE+ and NE– of the ECM connector.HINT:The correct waveforms are as shown.
NG Replace crankshaft position sensor.
OK
2 Check for open and short in harness and connector between ECM and crankshaft position sensor (See page IN–28).
NG Repair or replace harness or connector.
OK
3 Inspect sensor installation and teeth of crank angle sensor plate (See page EM–11).
NG Tighten sensor. Replace crank angle sensorplate.
OK
Check and replace ECM (See page IN–28).
–DIAGNOSTICS ENGINEDI–73
237Author: Date:
2000 MR2 (RM760U)
DTC P0340 Camshaft Position Sensor Circuit Malfunction
CIRCUIT DESCRIPTIONCamshaft position sensor (G signal) consists of a magnet,iron core and pickup coil.The G signal rotor has 3 teeth on its outer circumference and is mounted on the intake camshaft.When the camshafts rotate, the protrusion on the signal plate and the air gap on the pickup coil change,causing fluctuations in the magnetic field and generating an electromotive force in the pickup coil.The NE signal plate (crank angle sensor plate) has 34 teeth and is installed on the crankshaft. The NE signalsensor generates 34 signals at every engine revolution. The ECM detects the standard crankshaft anglebased on the G signals, the actual crankshaft angle and the engine speed by the NE signals.
DTC No. DTC Detection Condition Trouble Area
P0340
No camshaft position sensor signal to ECM during cranking (2
trip detection logic)Open or short in camshaft position sensor circuit
Camshaft position sensorP0340
No camshaft position sensor signal to ECM with engine speed
600 rpm or more
Camshaft osition sensor
Intake camshaft
ECM
WIRING DIAGRAMRefer to DTC P0335 on page DI–71.
INSPECTION PROCEDUREHINT:Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze frame recordsthe engine conditions when the malfunction is detected. When troubleshooting, it is useful for determiningwhether the vehicle was running or stopped, the engine was warmed up or not, the air–fuel ratio was leanor rich, etc. at the time of the malfunction.
1 Check resistance of camshaft position sensor (See page IG–1).
Reference: INSPECTION USING OSCILLOSCOPERefer to DTC P0335 on page DI–71.
NG Replace camshaft position sensor.
OK
2 Check for open and short in harness and connector between ECM and camshaftposition sensor (See page IN–28).
NG Repair or replace harness or connector.
OK
DI38D–03
DI–74–DIAGNOSTICS ENGINE
238Author: Date:
2000 MR2 (RM760U)
3 Inspect sensor installation and signal rotor teeth of intake camshaft (See pageEM–11).
NG Tighten sensor. Replace intake camshaft.
OK
Check and replace ECM (See page IN–28).
FI7081
Waveform of Heated OxygenSensor in front of Catalyst Normal Catalyst Waveform of Heated Oxygen
Sensor behind Catalyst
FI7132
Engine Speed
2,500 – 3,000 rpm
Idling
IG SW OFF
Warmed up 3 min. or so Check Time(a)
(c) (d)
(b)
–DIAGNOSTICS ENGINEDI–75
239Author: Date:
2000 MR2 (RM760U)
DTC P0420 Catalyst System Efficiency Below Threshold(Bank 1)
CIRCUIT DESCRIPTIONThe ECM compares the waveform of the heated oxygen sensor located in front of the catalyst with the wave-form of the heated oxygen sensor located behind the catalyst to determine whether or not catalyst perfor-mance has deteriorated.Air–fuel ratio feedback compensation keeps the waveform of the heated oxygen sensor in front of the cata-lyst repeatedly changing back and forth from rich to lean.If the catalyst is functioning normally, the waveform of the heated oxygen sensor behind the catalyst switchesback and forth between rich and lean much more slowly than the waveform of the heated oxygen sensorin front of the catalyst.But when both waveforms change at a similar rate, it indicates that catalyst performance has deteriorated.
DTC No. DTC Detection Condition Trouble Area
P0420
After engine and catalyst are warmed up, and while vehicle is
driven within set vehicle and engine speed range, waveforms
of oxygen sensors (bank 1 sensor 1 and bank 1 sensor 2)
have same amplitude (2 trip detection logic)
Gas leakage on exhaust system
Heated oxygen sensor
Three–way catalytic converter
CONFIRMATION ENGINE RACING PATTERN
DI38G–04
FI6514
OX Signal Waveform (Oscilloscope)
1.0 V
0 V
200 msec. /Division
DI–76–DIAGNOSTICS ENGINE
240Author: Date:
2000 MR2 (RM760U)
(a) Connect the TOYOTA hand–held tester to the DLC3, or connect the probe of the oscilloscope betweenterminals OX1A, OX1B, OX2A and E1 of the ECM connector.
(b) Start the engine and warm it up with all the accessories switched OFF until water temperature is stable.(c) Race the engine at 2,500 – 3,000 rpm for about 3 min.(d) After confirming that the waveforms of the heated oxygen sensor (bank 1, 2 sensor 1 (OX1A, OX2A)),
oscillate around 0.5 V during feedback to the ECM, check the waveform of the heated oxygen sensor(bank 1 sensor 2 (OX1B)).
HINT: If there is a malfunction in the system, the waveform of the
heated oxygen sensor (bank 1 sensor 2 (OX1B)), is al-most the same as that of the heated oxygen sensor (bank1, 2 sensor 1 (OX1A, OX2A)), on the left.
There are some cases where, even though a malfunctionexists, the MIL may either light up or not light up.
INSPECTION PROCEDUREHINT:Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze frame recordsthe engine conditions when the malfunction is detected. When troubleshooting, it is useful for determiningwhether the vehicle was running or stopped, the engine was warmed up or not, the air–fuel ratio was leanor rich, etc. at the time of the malfunction.
1 Are there any other codes (besides DTC P0420) being output?
YES Go to relevant DTC chart (See page DI–14).
NO
2 Check gas leakage on exhaust system.
NG Repair or replace.
OK
3 Check heated oxygen sensor (bank 1, 2 sensor 1) (See page DI–47).
NG Repair or replace.
–DIAGNOSTICS ENGINEDI–77
241Author: Date:
2000 MR2 (RM760U)
OK
4 Check heated oxygen sensor (bank 1 sensor 2) (See page DI–56).
NG Repair or replace.
OK
Replace three–way catalytic converter.
A10140
ECM
VSVfor EVAP
Charcoal Canister Fuel Tank
Fig. 1
(2)
(3)
(4)
(6)
(8)(9)
(1)(5)
Fuel Tank OverFill Check Valve
(7)
Vapor PressureSensor
VSV forCCV
VSV for Pressure SwitchingValve
(10)
(11)
DI–78–DIAGNOSTICS ENGINE
242Author: Date:
2000 MR2 (RM760U)
DTC P0440 Evaporative Emission Control SystemMalfunction
CIRCUIT DESCRIPTIONThe vapor pressure sensor, VSV for canister closed valve (CCV) and VSV for pressure switching valve areused to detect abnormalities in the evaporative emission control system.The ECM decides whether there is an abnormality in the evaporative emission control system based on thevapor pressure sensor signal.DTC P0440 is recorded by the ECM when evaporative emissions leak from the components within the dottedline in Fig. 1 below, or when the vapor pressure sensor malfunctions.
DTC No. DTC Detection Condition Trouble Area
P0440Fuel tank pressure is atmospheric pressure after vehicle is
driven for 20 min. (2 trip detection logic)
Hose or tube cracked, holed, damaged or loose seal ((3) in
Fig. 1)
Fuel tank cap incorrectly installed
Fuel tank cap cracked or damaged
Vacuum hose cracked, holed, blocked, damaged or discon-
nected ((1) or (2) in Fig. 1)
Fuel tank cracked, holed or damaged
Charcoal canister cracked, holed or damaged
Open or short in vapor pressure sensor circuit
Vapor pressure sensor
Fuel tank over fill check valve cracked or damaged
ECM
DI7DF–01
A13047
ECM
VC
E2
TBP
CCV
EVP1
2
E4
V4VSV for PressureSwitching Valve
4
E2
18
E4
23
E3
17
E5
4
E4
3
2
1
V3Vapor Pressure Sensor
1
V1 VSV for CanisterClosed Valve
2
V2 VSV for EVAP
12
12
2
1
1
1
6
5
10BA1 BC3
9
5
2
5
1B–R L–W
L–R
G–B
BR
L
W
B
FL Block
EFI2
From Terminal 3 ofEFI MAIN Relay(See page DI–132)
L–RL–R
G–B
BRBR
L–WB–R
B–R
B–R B–R
B–R
PTNKBA1
BA1 BC3
BB1 BB1
BC1
VCC
PTNK
E
–DIAGNOSTICS ENGINEDI–79
243Author: Date:
2000 MR2 (RM760U)
WIRING DIAGRAM
INSPECTION PROCEDUREHINT: If DTC P0441, P0446, P0450 or P0451 is output after DTC P0440, first troubleshoot DTC P0441,
P0446, P0450 or P0451. If no malfunction is detected, troubleshoot DTC P0440 next. Ask the customer whether, after the MIL came on, the customer found the fuel tank cap loose and tight-
ened it. Also ask the customer whether the fuel tank cap was loose when refuelling. If the fuel tank capwas not loose, the DTC is suspected. If the fuel tank cap was not loose or if the customer was not sureif it was loose, troubleshoot according to the following procedure.
Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze framerecords the engine conditions when the malfunction is detected. When troubleshooting, it is useful fordetermining whether the vehicle was running or stopped, the engine was warmed up or not, the air–fuelratio was lean or rich, etc. at the time of the malfunction.
When the ENGINE RUN TIME in the freeze frame data is less than 200 seconds, carefully check theVSV for EVAP, charcoal canister and vapor pressure sensor.
A10274
DI–80–DIAGNOSTICS ENGINE
244Author: Date:
2000 MR2 (RM760U)
1 Check whether hose close to fuel tank have been modified, and check whetherthere are signs of any accident near fuel tank or charcoal canister.
CHECK:Check for cracks, deformation and loose connection of the fol-lowing parts: Fuel tank Charcoal canister Fuel tank filler pipe Hoses and tubes around fuel tank and charcoal canister
NG Repair or replace.
OK
2 Check that fuel tank cap is TOYOTA genuine parts.
NG Replace with TOYOTA genuine parts.
OK
3 Check that fuel tank cap is correctly installed.
NG Correctly install fuel tank cap.
OK
4 Check fuel tank cap (See page EC–6).
NG Replace fuel tank cap.
OK
–DIAGNOSTICS ENGINEDI–81
245Author: Date:
2000 MR2 (RM760U)
5 Check fuel inlet pipe for damage.
PREPARATION:Remove the fuel tank cap.CHECK:Visually inspect the fuel inlet pipe for damage.
NG Replace fuel inlet pipe.
OK
6 Check vacuum hoses between vapor pressure sensor and fuel tank, and char-coal canister and VSV for pressure switching valve.
CHECK:(a) Check that the vacuum hose is connected correctly.(b) Check the vacuum hose for looseness and disconnection.(c) Check the vacuum hose for cracks, hole and damage.
NG Repair or replace.
OK
7 Check hose and tube between fuel tank and charcoal canister.
CHECK:(a) Check for proper connection of the fuel tank and fuel evap pipe (See page EC–6), fuel evap pipe and
fuel tube under the floor, fuel tube under the floor and charcoal canister.(b) Check the hose and tube for cracks, hole and damage.
NG Repair or replace.
OK
8 Check charcoal canister for cracks, hole and damage (See page EC–6).
NG Replace charcoal canister.
OK
A12802
ON
E2PTNK
(+)(–)
DI–82–DIAGNOSTICS ENGINE
246Author: Date:
2000 MR2 (RM760U)
9 Check voltage between terminals VC and E2 of ECM connector (See page DI–37, step 5).
NG Check and replace ECM (See page IN–28).
OK
10 Check voltage between terminals PTNK and E2 of ECM connectors.
PREPARATION:(a) Disconnect the ECM with connector from body panel
(See page SF–62).(b) Remove the fuel tank cap.(c) Turn the ignition switch ON.CHECK:Measure the voltage between terminals PTNK and E2 of theECM connectors.OK:
Voltage: 3.0 – 3.6 V
OK Go to step 12.
NG
11 Check for open and short in harness and connector between vapor pressuresensor and ECM (See page IN–28).
NG Repair or replace harness or connector.
OK
Replace vapor pressure sensor.
12 Check fuel tank and fuel tank over fill check valve for cracks and damage.
NG Replace fuel tank or fuel tank over fill checkvalve.
–DIAGNOSTICS ENGINEDI–83
247Author: Date:
2000 MR2 (RM760U)
OK
It is likely that vehicle user did not properly close fuel tank cap. Please explain to customer howto properly install fuel tank cap.
A10142
ECM
Fuel TankCharcoal Canister
VSV forEVAP (1)
Fig. 1
(2)
(3)
(4)(5)
(6)
(7)
Fuel Tank Over Fill Check Valve
(10)
(9)
Vapor Pressure Sensor
VSV forCCV
VSV for Pressure Switching Valve
(8) (11)
DI–84–DIAGNOSTICS ENGINE
248Author: Date:
2000 MR2 (RM760U)
DTC P0441 Evaporative Emission Control System Incor-rect Purge Flow
DTC P0446 Evaporative Emission Control System VentControl Malfunction
CIRCUIT DESCRIPTIONThe vapor pressure sensor, VSV for canister closed valve (CCV), VSV for pressure switching valve are usedto detect abnormalities in the evaporative emission control system.The ECM decides whether there is an abnormality in the evaporative emission control system based on thevapor pressure sensor signal.DTCs P0441 and P0446 are recorded by the ECM when evaporative emissions leak from the componentswithin the dotted line in Fig. 1 below, or when there is a malfunction in the VSV for EVAP, the VSV for pressureswitching valve, or in the vapor pressure sensor itself.
DI6OS–02
–DIAGNOSTICS ENGINEDI–85
249Author: Date:
2000 MR2 (RM760U)
DTC No. DTC Detection Condition Trouble Area
P0441
Pressure in charcoal canister does not drop during purge con-
trol (2 trip detection logic)
Vacuum hose cracks, holed, blocked, damaged or discon-
nected ((1), (2), (3), (4), (5), (6), (7), (8), (9), (10) and(11) in
Fi 1)P0441During purge cut–off, pressure in charcoal canister is very low
compared with atmospheric pressure (2 trip detection logic)
Fig. 1)
Fuel tank cap incorrectly installed
Open or short in vapor pressure sensor circuit
When VSV for pressure switching valve is turned OFF, pres-
sure in fuel tank is maintained at atmospheric pressure (2 trip
detection logic)
O en or short in va or ressure sensor circuit
Vapor pressure sensor
Open or short in VSV circuit for EVAP
VSV for EVAP
Open or short in VSV circuit for CCV
P0446
When VSV for pressure switching valve is OFF, ECM judges
that there is no continuity between vapor pressure sensor and
fuel tank (2 trip detection logic)
Open or short in VSV circuit for CCV
VSV for CCV
Open or short in VSV circuit for pressure switching valve
VSV for pressure switching valve
F l t k k d h l d d dWhen VSV for CCV is ON, pressure in charcoal canister and
fuel tank is maintained at atmospheric pressure (2 trip detec-
tion logic)
Fuel tank cracked, holed ordamaged
Charcoal canister cracked, holed or damaged
Fuel tank over fill check valve cracked or damaged
ECM
WIRING DIAGRAMRefer to DTC P0440 on page DI–78.
INSPECTION PROCEDUREHINT: If DTC P0441, P0446, P0450 or P0451 is output after DTC P0440, first troubleshoot DTC P0441,
P0446, P0450 or P0451. If no malfunction is detected, troubleshoot DTC P0440 next. Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze frame
records the engine conditions when the malfunction is detected. When troubleshooting, it is useful fordetermining whether the vehicle was running or stopped, the engine was warmed up or not, the air–fuelratio was lean or rich, etc. at the time of the malfunction.
When the ENGINE RUN TIME in the freeze frame data is less than 200 seconds, carefully check theVSV for EVAP, charcoal canister and vapor pressure sensor.
TOYOTA hand–held tester:
1 Check whether hose close to fuel tank have been modified, and check whetherthere are signs of any accident near fuel tank or charcoal canister (See pageDI–78, step 1).
NG Repair or replace.
OK
2 Check that fuel tank cap is TOYOTA genuine parts.
NG Replace with TOYOTA genuine parts.
OK
DI–86–DIAGNOSTICS ENGINE
250Author: Date:
2000 MR2 (RM760U)
3 Check that fuel tank cap is correctly installed.
NG Correctly install fuel tank cap.
OK
4 Check fuel tank cap (See page EC–6).
NG Replace fuel tank cap.
OK
5 Check fuel inlet pipe for damage (See page DI–78, step 5).
NG Replace fuel inlet pipe.
OK
6 Check vacuum hoses between vapor pressure sensor and fuel tank, and char-coal canister and VSV for pressure switching valve.
NG Repair or connect VSV or sensor connector.
OK
7 Check hose and tube between fuel tank and charcoal canister (See page DI–78step 7).
NG Repair or replace.
OK
–DIAGNOSTICS ENGINEDI–87
251Author: Date:
2000 MR2 (RM760U)
8 Check VSV connector for EVAP, VSV connector for CCV, VSV connector for pres-sure switching valve and vapor pressure sensor connector for looseness anddisconnection.
NG Repair or connect VSV or sensor connector.
OK
9 Check vacuum hoses ((8), (9), (10) and (11) in Fig. 1 in circuit description).
CHECK:(a) Check that the vacuum hose is connected correctly.(b) Check the vacuum hose for looseness and disconnection.(c) Check the vacuum hose for cracks, hole, damage and blockage.
NG Repair or replace.
OK
10 Check voltage between terminals VC and E2 of ECM connector (See page DI–78 step 9).
NG Check and replace ECM (See page IN–28).
OK
11 Check voltage between terminals PTNK and E2 of ECM connectors (See pageDI–78, step 10).
OK Go to step 13.
NG
12 Check for open and short in harness and connector between vapor pressuresensor and ECM (See page IN–28).
A13071
To Throttle Body
DI–88–DIAGNOSTICS ENGINE
252Author: Date:
2000 MR2 (RM760U)
NG Repair or replace harness or connector.
OK
Replace vapor pressure sensor.
13 Check purge flow.
PREPARATION:(a) Connect the TOYOTA hand–held tester to the DLC3.(b) Select the ACTIVE TEST mode on the TOYOTA hand–
held tester.(c) Disconnect the vacuum hose from the VSV for the EVAP
from the charcoal canister.(d) Start the engine.CHECK:When the VSV for the EVAP is operated by the TOYOTA hand–held tester, apply the disconected hose to your finger to checkthe suction.OK:
VSV is ON: Disconnected hose sucks.VSV is OFF: Disconnected hose does not suck.
OK Go to step 17.
NG
14 Check vacuum hose between intake manifold and VSV for EVAP, and VSV forEVAP and charcoal canister.
CHECK:(a) Check that the vacuum hose is connected correctly.(b) Check the vacuum hose for looseness and disconnection.(c) Check the vacuum hose for cracks, hole, damage and blockage.
NG Repair or replace.
OK
A12540VSV is ONVSV is OFF
ON
Air
F
Air
EF
E
–DIAGNOSTICS ENGINEDI–89
253Author: Date:
2000 MR2 (RM760U)
15 Check operation of VSV for EVAP (See page SF–49).
OK Go to step 16.
NG
Replace VSV and charcoal canister, and then clean vacuum hoses between throttle body andVSV for EVAP, and VSV for EVAP and charcoal canister.
16 Check for open and short in harness and connector between EFI main relay(Marking: EFI MAIN) and VSV for EVAP, and VSV for EVAP and ECM (See pageIN–28).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN–28).
17 Check VSV for CCV.
PREPARATION:(a) Connect the TOYOTA hand–held tester to the DLC3.(b) Disconnect the vacuum hose for the VSV for the CCV
from the charcoal canister.(c) Turn the ignition switch ON and push the TOYOTA hand–
held tester main switch ON.(d) Select the ACTIVE TEST mode on the TOYOTA hand–
held tester.CHECK:Check the VSV operation when it is operated by the TOYOTAhand–held tester.OK:
VSV is ON: Air does not flow from port E to port F.VSV is OFF: Air from port E flows out through port F.
OK Go to step 21.
DI–90–DIAGNOSTICS ENGINE
254Author: Date:
2000 MR2 (RM760U)
NG
18 Check vacuum hose between VSV for CCV and charcoal canister.
CHECK:(a) Check that the vacuum hose is connected correctly.(b) Check the vacuum hose for looseness and disconnection.(c) Check the vacuum hose for cracks, hole damage and blockage.
NG Repair or replace.
OK
19 Check operation of VSV for CCV (See page SF–50).
OK Go to step 20.
NG
Replace VSV and charcoal canister, and then clean vacuum hose between charcoal canister andVSV for CCV.
20 Check for open and short in harness and connector between EFI main relay andVSV for CCV, and VSV for CCV and ECM (See page IN–28).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN–28).
A12541
VSV is ON VSV is OFF
ON
Air Air
E
F
E
F
–DIAGNOSTICS ENGINEDI–91
255Author: Date:
2000 MR2 (RM760U)
21 Check VSV for pressure switching valve .
PREPARATION:(a) Connect the TOYOTA hand–held tester to the DLC3.(b) Turn the ignition switch ON and push the TOYOTA hand–
held tester main switch ON.(c) Select the ACTIVE TEST mode on the TOYOTA hand–
held tester.CHECK:Check the VSV operation when it is operated by the TOYOTAhand–held tester.OK:
VSV is ON: Air from port E flows out through port F.VSV is OFF: Air does not flow from port E to port F.
OK Go to step 24.
NG
22 Check operation of VSV for pressure switching valve (See page SF–53).
OK Go to step 23.
NG
Replace VSV and charcoal canister, and then clean vacuum hose between charcoal canister andVSV for pressure switching valve, and VSV for pressure switching valve and fuel tank.
23 Check for open and short in harness and connector between EFI main relay andVSV for pressure switching valve, and VSV for pressure switching valve andECM (See page IN–28).
NG Repair or replace harness or connector.
OK
BE6653
A10620
A12802
A12804
START
ON
VSV for pressure
Switching Valve
OFF
VSV for EVAP
30 sec.
ON
OFF
E2 PTNK
(–) (+)
ON
OFF
VSV for CCV
MeasureVoltage
DI–92–DIAGNOSTICS ENGINE
256Author: Date:
2000 MR2 (RM760U)
Check and replace ECM (See page IN–28).
24 Check fuel tank.
PREPARATION:(a) Disconnect the ECM with connector from body panel
(See page SF–62).(b) Connect the TOYOTA hand–held tester to the DLC3.(c) Select the ACTIVE TEST mode on the TOYOTA hand–
held tester.(d) Start the engine.(e) The VSV for the CCV is ON by the TOYOTA hand–held
tester.(f) The VSV for the EVAP is OFF, and the VSV for the pres-
sure switching valve is ON by the TOYOTA hand–heldtester and remains on for 30 sec.
CHECK:Measure the voltage between terminals PTNK and E2 of theECM connectors after switching the VSV for the EVAP fromOFF to ON, and the VSV for the pressure switching valve fromON to OFF.OK:
Voltage: 2.5 V or less
NG Replace fuel tank.
OK
BE6653
A10621
A12802
A12805
START
ON
OFF
ON
OFF
ON
OFF
VSV for pressure
Switching Valve
VSV for EVAP
VSV for CCV
30 sec. MeasureVoltage
E2
PTNK
(–) (+)
–DIAGNOSTICS ENGINEDI–93
257Author: Date:
2000 MR2 (RM760U)
25 Check charcoal canister.
PREPARATION:(a) Disconnect the ECM with connector from body panel
(See page SF–62).(b) Connect the TOYOTA hand–held tester to the DLC3.(c) Select the ACTIVE TEST mode on the TOYOTA hand–
held tester.(d) Start the engine.(e) The VSV for the CCV and the VSV for the pressure
switching valve are ON by the TOYOTA hand–held tester.(f) The VSV for the EVAP is OFF by the TOYOTA hand–held
tester and remains on for 30 sec.CHECK:Measure the voltage between terminals PTNK and E2 of theECM connectors after switching the VSV for the EVAP fromOFF to ON.OK:
Voltage: 2.5 V or less
NG Replace charcoal canister.
OK
26 Remove charcoal canister and check it (See page EC–6).
NG Replace charcoal canister.
OK
27 Check fuel tank over fill check valve (See page EC–6).
NG Replace fuel tank over fill check valve or fueltank.
OK
Check and replace charcoal canister (Seepage EC–5).
DI–94–DIAGNOSTICS ENGINE
258Author: Date:
2000 MR2 (RM760U)
OBD II scan tool (excluding TOYOTA hand–held tester):
1 Check whether hose close to fuel tank have been modified, and check whetherthere are signs of any accident near fuel tank or charcoal canister (See pageDI–78, step 1).
NG Repair or replace.
OK
2 Check that fuel tank cap is TOYOTA genuine parts.
NG Replace with TOYOTA genuine parts.
OK
3 Check that fuel tank cap is correctly installed.
NG Correctly install fuel tank cap.
OK
4 Check fuel tank cap (See page EC–6).
NG Replace fuel tank cap.
OK
5 Check fuel inlet pipe neck for damage.
NG Replace fuel inlet pipe.
–DIAGNOSTICS ENGINEDI–95
259Author: Date:
2000 MR2 (RM760U)
OK
6 Check vacuum hoses between vapor pressure sensor and fuel tank, and char-coal canister and VSV for pressure switching valve.
NG Repair or connect VSV or sensor connector.
OK
7 Check hose and tube between fuel tank and charcoal canister (See page DI–78step 7).
NG Repair or replace.
OK
8 Check VSV connector for EVAP, VSV connector for CCV, VSV connector for pres-sure switching valve and vapor pressure sensor connector for looseness anddisconnection.
NG Repair or connect VSV or sensor connector.
OK
9 Check vacuum hoses ((8), (9) , (10) and (11) in Fig. 1 in circuit description).
CHECK:(a) Check that the vacuum hose is connected correctly.(b) Check the vacuum hose for looseness and disconnection.(c) Check the vacuum hose for cracks, hole damage and blockage.
NG Repair or replace.
OK
DI–96–DIAGNOSTICS ENGINE
260Author: Date:
2000 MR2 (RM760U)
10 Check voltage between terminals VC and E2 of ECM connector (See page DI–78 step 9).
NG Check and replace ECM (See page IN–28).
OK
11 Check voltage between terminals PTNK and E2 of ECM connectors (See page DI–78, step 10).
OK Go to step 13.
NG
12 Check for open and short in harness and connector between vapor pressuresensor and ECM (See page IN–28).
NG Repair or replace harness or connector.
OK
Replace vapor pressure sensor.
A12806
E
F
ON
F
E
VSV is ON VSV is OFF
EVP1
ON
OFF
Air Air
–DIAGNOSTICS ENGINEDI–97
261Author: Date:
2000 MR2 (RM760U)
13 Check VSV for EVAP.
PREPARATION:(a) Disconnect the ECM with connector from body panel
(See page SF–62).(b) Turn the ignition switch ON.CHECK:Check the VSV function.
(1) Connect between terminal EVP1 of the ECM con-nector and body ground (VSV ON).
(2) Disconnect between terminal EVP1 of the ECMconnector and body ground (VSV OFF).
OK:(1) VSV is ON:Air from port E flows out through port F.(2) VSV is OFF:Air from port E flows out through port F with a little dif-ficultly.
OK Go to step 16.
NG
14 Check operation of VSV for EVAP (See page SF–49).
NG Go to step 15.
NG
Replace VSV and clean vacuum hoses between throttle body and VSV for EVAP, and VSV forEVAP and charcoal canister, and then check charcoal canister.
15 Check for open and short in harness and connector between EFI main relay(Marking: EFI MAIN) and VSV for EVAP, and VSV for EVAP and ECM (See page IN–28)
NG Repair or replace harness or connector.
OK
A12540 A12807
VSV is ONVSV is OFF
Air
E
F
Air
E
F
ONCCV
ONOFF
DI–98–DIAGNOSTICS ENGINE
262Author: Date:
2000 MR2 (RM760U)
Check and replace ECM (See page IN–28).
16 Check VSV for CCV.
PREPARATION:(a) Disconnect the ECM with connector from body panel
(See page SF–62).(b) Turn the ignition switch ON.CHECK:Check the VSV function.
(1) Connect between terminal CCV of the ECM con-nector and body ground (VSV ON).
(2) Disconnect between terminal CCV of the ECM con-nector and body ground (VSV OFF).
OK:VSV is ON:Air does not flow from port E to port F.VSV is OFF:Air from port E flows out through port F.
OK Go to step 19.
NG
17 Check operation of VSV for CCV (See page SF–51).
OK Go to step 18.
NG
Replace VSV and charcoal canister, and then clean vacuum hoses between charcoal canisterand VSV for CCV.
18 Check for open and short in harness and connector between EFI main relay(Marking: EFI MAIN) and VSV for CCV , and VSV for CCV and ECM (See page IN–28).
NG Repair or replace harness or connector.
A12808
VSV is ON VSV is OFF
Air
E
F
Air
E
F
ON
TBP
ONOFF
–DIAGNOSTICS ENGINEDI–99
263Author: Date:
2000 MR2 (RM760U)
OK
Check and replace ECM (See page IN–28).
19 Check VSV for pressure switching valve.
PREPARATION:(a) Disconnect the ECM with connector from body panel
(See page SF–62).(b) Turn the ignition switch ON.CHECK:Check the VSV function.
(1) Connect between terminal TBP of the ECM connec-tor and body ground (VSV ON).
(2) Disconnect between terminal TBP of the ECM con-nector and body ground (VSV OFF).
OK:(1) VSV is ON:Air from port E flows out through port F.(2) VSV is OFF:Air does not flow from port E to port F.
OK Go to step 22.
NG
20 Check operation of VSV for pressure switching valve (See page SF–53).
OK Go to step 21.
NG
Replace VSV and charcoal canister, and then clean vacuum hoses between charcoal canisterand VSV for pressure switching valve, and VSV for pressure switching valve and fuel tank.
21 Check for open and short in harness and connector between EFI main relay andVSV for pressure switching valve , and VSV for pressure switching valve and ECM(See page IN–28).
DI–100–DIAGNOSTICS ENGINE
264Author: Date:
2000 MR2 (RM760U)
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN–28).
22 Check fuel tank over fill check valve (See page EC–6).
NG Replace fuel tank over fill check valve or fueltank.
OK
Check and replace charcoal canister (Seepage EC–5).
A10145
ECM
Fuel TankCharcoal Canister
VSV forEVAP
Fuel Tank Over Fill Check Valve
Vapor Pressure Sensor
VSV forCCV
VSV for Pressure Switching Valve
–DIAGNOSTICS ENGINEDI–101
265Author: Date:
2000 MR2 (RM760U)
DTC P0450 Evaporative Emission Control System Pres-sure Sensor Malfunction
DTC P0451 Evaporative Emission Control System Pres-sure Sensor Range/Performance
CIRCUIT DESCRIPTIONThe vapor pressure sensor, VSV for canister closed valve (CCV) and VSV for pressure switching valve areused to detect abnormalities in the evaporative emission control system.The ECM decides whether there is an abnormality in the evaporative emission control system based on thevapor pressure sensor signal.DTC P0450 or P0451 is recorded by the ECM when the vapor pressure sensor malfunctions.
DTC No. DTC Detection Condition Trouble Area
P0450
10 seconds or less after engine starting condition (a) or (b)
continues for 7 seconds or more: (2 trip detection logic)
(a) Vapor pressure sensor value < –4.0 kPa (–30 mmHg, –1.2
in.Hg)
(b) Vapor pressure sensor value 2.0 kPa (15 mmHg, 0.6
in.Hg)Open or short in vapor pressure sensor circuit
Vapor pressure sensor
P0451
Vapor pressure sensor output extremely changes under condi-
tions of (a) or (b): (2 trip detection logic)
(a) Vehicle speed: 0 km/h (0mph), Engine speed: Idling and
VSV for pressure switching valve is OFF
(b) High vapor pressure sensor
Va or ressure sensor
ECM
DI1K0–08
DI–102–DIAGNOSTICS ENGINE
266Author: Date:
2000 MR2 (RM760U)
WIRING DIAGRAMRefer to DTC P0440 on page DI–78.
INSPECTION PROCEDUREHINT: If DTC P0441, P0446, P0450 or P0451 is output after DTC P0440, first troubleshoot DTC P0441,
P0446 P0450 or P0451. If no malfunction is detected, troubleshoot DTC P0440 next. Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze frame
records the engine conditions when the malfunction is detected. When troubleshooting, it is useful fordetermining whether the vehicle was running or stopped, the engine was warmed up or not, the air–fuelratio was lean or rich, etc. at the time of the malfunction.
When the ENGINE RUN TIME in the freeze frame data is less than 200 seconds, carefully check theVSV for EVAP, charcoal canister and vapor pressure sensor.
1 Check voltage between terminals VC and E2 of ECM connector (See pageDI–78).
NG Check and replace ECM (See page IN–28).
OK
2 Check voltage between terminals PTNK and E2 of ECM connectors (See pageDI–78).
OK Check and replace ECM (See page IN–28).
NG
3 Check for open and short in harness and connector between vapor pressuresensor and ECM (See page IN–28).
NG Repair or replace harness or connector.
OK
Replace vapor pressure sensor.
A00022
4–pulse
CombinationMeter
ECM
4–pulse
FromSpeed Sensor ABS ECU
A13048
Combination Meter
5C10 E3
V–W V–W
ECM
SPD
5 V
22IC28
–DIAGNOSTICS ENGINEDI–103
267Author: Date:
2000 MR2 (RM760U)
DTC P0500 Vehicle Speed Sensor Malfunction
CIRCUIT DESCRIPTIONThe speed sensor for ABS detects the wheel speed and sends the appropriate signals to the ABS ECU.The ECU converts these signals into a 4–pulse signal and outputs it to the combination meter.After this signal is converted into a more precise rectangular waveform by the waveform shaping circuit in-side the combination meter, it is then transmitted to the ECM. The ECM determines the vehicle speed basedon the frequency of these pulse signals.
DTC No. DTC Detection Condition Trouble Area
P0500
No vehicle speed sensor signal to ECM under following condi-
tion: (2 trip detection logic)
( ) V hi l i b i d i
Combination meter
Open or short in vehicle speed sensor circuit
V hi l dP0500 (a) Vehicle is being driven
(b) Clutch or brake slips or gear is broken (2–trip detection
logic)
Vehicle speed sensor
ABS ECU
ECM
WIRING DIAGRAM
DI38H–03
A12809
E3 Connector
SPD
DI–104–DIAGNOSTICS ENGINE
268Author: Date:
2000 MR2 (RM760U)
INSPECTION PROCEDUREHINT:Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze frame recordsthe engine conditions when the malfunction is detected. When troubleshooting, it is useful for determiningwhether the vehicle was running or stopped, the engine was warmed up or not, the air–fuel ratio was leanor rich, etc. at the time of the malfunction.
1 Check operation of speedometer.
CHECK:Drive the vehicle and check if the operation of the speedometer in the combination meter is normal.HINT:The vehicle speed sensor is operating normally if the speedometer display is normal.
NG Check speedometer circuit (See page BE–38).
OK
2 Check for short in harness and connector between terminal SPD of ECM connec-tor and body ground.
PREPARATION:(a) Disconnect the ECM with connector from body panel
(See page SF–62).(b) Disconnect the E3 connector from the ECM.CHECK:Check the continuity between terminal SPD of the ECM con-nector and body ground.OK:
No continuity (1 M Ω or higher)
NG Repair or replace harness or connector.
OK
A12810
E3 Connector
ON
SPD
(–) (+)
–DIAGNOSTICS ENGINEDI–105
269Author: Date:
2000 MR2 (RM760U)
3 Check voltage between terminal SPD of ECM connector and body ground.
PREPARATION:(a) Disconnect the ECM with connector from body panel
(See page SF–62).(b) Disconnect the E3 connector from the ECM.(c) Turn the ignition switch ON.CHECK:Measure the voltage between terminal SPD of the ECM con-nector and body ground.OK:
Voltage: 9 – 14 V
NG Repair or replace harness and connector be-tween combination meter and ECM (See pageIN–28).
OK
Check and replace ECM (See page IN–28).
P01559
Throttle Valve
To Cylinder
ECMSignal
FromAirCleaner
ValveIAC Valve
Intake AirChamber
A12546
I1IAC Valve
ECM
RSO
18
E51
W–B
3
2
E0121E5
G
FromTerminal 3 ofEFI MAIN Relay(See page DI–132)
BVISC
DUTY
GND
5BC2
B
DI–106–DIAGNOSTICS ENGINE
270Author: Date:
2000 MR2 (RM760U)
DTC P0505 Idle Control System Malfunction
CIRCUIT DESCRIPTIONThe rotary solenoid type IAC valve is located on the throttlebody and intake air bypassing the throttle valve is directed tothe IAC valve through a passage.In this way the intake air volume bypassing the throttle valve isregulated, controlling the engine speed.The ECM operates only the IAC valve to perform idle–up andprovide feedback for the target idling speed.
DTC No. DTC Detection Condition Trouble Area
P0505Idle speed continues to vary greatly from target speed
(2 trip detection logic)
Open or short in IAC valve circuit
IAC valve is stuck or closed
Open or short in A/C switch circuit
Air induction system
ECM
WIRING DIAGRAM
INSPECTION PROCEDUREHINT:Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze frame recordsthe engine conditions when the malfunction is detected. When troubleshooting, it is useful for determiningwhether the vehicle was running or stopped, the engine was warmed up or not, the air–fuel ratio was leanor rich, etc. at the time of the malfunction.
DI38I–05
A11500
BE6653
A12741
ON
RSO
ConnectorE5
(–)(+)
–DIAGNOSTICS ENGINEDI–107
271Author: Date:
2000 MR2 (RM760U)
1 Check engine idle speed.
PREPARATION:(a) Warm up the engine to normal operating temperature.(b) Switch off all the accessories.(c) Switch off the A/C.(d) Shift the transmission into neutral position.(e) Connect the OBD II scan tool or TOYOTA hand–held tester to the DLC3 on the vehicle.CHECK:Check the difference of engine speed in less than 5 sec. and more than 5 sec.OK:
Difference of engine speed: More than 100 rpm.
OK Go to step 6.
NG
2 Check voltage between terminals RSO of ECM connector and body ground.
PREPARATION:(a) Disconnect the ECM with connector from body panel
(See page SF–62).(b) Disconnect the E5 connector from ECM.(c) Turn the ignition switch ON.CHECK:Measure the voltage between terminals RSO of the ECM con-nector and body ground,OK:
Voltage: 9 – 14 V
OK Go to step 4.
NG
3 Check IAC valve (See page SF–38).
NG Replace IAC valve.
OK
DI–108–DIAGNOSTICS ENGINE
272Author: Date:
2000 MR2 (RM760U)
Check for open and short in harness andconnector between IAC valve and ECM (Seepage IN–28).
4 Check operation of IAC valve (See page SF–38).
NG Replace IAC valve.
OK
5 Check blockage of IAC valve and passage to bypass throttle valve.
NG Replace IAC valve.
OK
Check and replace ECM (See page IN–28).
6 Check for A/C signal circuit (See page AC–84).
NG Repair or replace.
OK
Check air induction system (See page SF–1).
–DIAGNOSTICS ENGINEDI–109
273Author: Date:
2000 MR2 (RM760U)
DTC P1300 Igniter Circuit Malfunction (No. 1)
DTC P1305 Igniter Circuit Malfunction (No. 2)
DTC P1310 Igniter Circuit Malfunction (No. 3)
DTC P1315 Igniter Circuit Malfunction (No. 4)
CIRCUIT DESCRIPTIONA Direct Ignition System (DIS) has been adopted. The DIS improves the ignition timing accuracy, reduceshigh–voltage loss, and enhances overall reliability of the ignition system by eliminating the distributor.The DIS is a 1–cylinder ignition system which ignites one cylinder with one ignition coil. In the 1–cylinderignition system, the spark plug is connected to the end of the secondary winding. High voltage generatedin the secondary winding is applied directly to the spark plug. The spark of the spark plug passes, from thecenter electrode to the ground electrode.The ECM determines ignition timing and outputs the ignition signals (IGT) for each cylinder. Based on IGTsignals, the power transistors in the igniter cuts off the current to the primary coil in the ignition coil suppliedto the spark plug connected to the end of the secondary coil. At the same time, the igniter also sends anignition confirmation signal (IGF) as a fail–safe measure to the ECM.
DTC No. DTC Detection Condition Trouble Area
P1300
P1305
P1310
P1315
No IGF signal to ECM while engine is running
Ignition system
Open or short in IGF and IGT circuit from ignition coil with
igniter
ignition coil with igniter
ECM
DI3HD–06
A13057
B
B–Y
L
L–W
B–R
W–B
1
2
3
4
Spark PlugECM
IGT1
IGT2
IGT3
IGT4
IGF
E510
11
12
13
25N1Noise Filter
1
2
3
4
1
2
3
4
1
2
3
4
Spark Plug
Spark Plug
Spark Plug
B–Y
B–Y
B–Y
L
B–Y
E5
E5
E5
E5
B–R
W–B
B–R
W–B
B–R
W–B
B–R
B–R
B–R
FromTerminal 3 ofIG2 Relay(See page DI–132)
W–B
W–B
W–B B–Y
B–Y
I2 No. 1Ignition Coilwith Igniter
I3 No. 2Ignition Coilwith Igniter
I4No. 3 Ignition Coilwith Igniter
I5No. 4 Ignition Coilwith IgniterB–R
1
EC
BC1 8
DI–110–DIAGNOSTICS ENGINE
274Author: Date:
2000 MR2 (RM760U)
WIRING DIAGRAM
A11506
BE6653
A12743
IGF
ON
(+) (–)
–DIAGNOSTICS ENGINEDI–111
275Author: Date:
2000 MR2 (RM760U)
INSPECTION PROCEDUREHINT: If DTC P1300 is displayed, check No. 1 ignition coil with igniter circuit. If DTC P1305 is displayed, check No. 2 ignition coil with igniter circuit. If DTC P1310 is displayed, check No. 3 ignition coil with igniter circuit. If DTC P1315 is displayed, check No. 4 ignition coil with igniter circuit. Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze frame
records the engine conditions when the malfunction is detected. When troubleshooting, it is useful fordetermining whether the vehicle was running or stopped, the engine was warmed up or not, the air–fuelratio was lean or rich, etc. at the time of the malfunction.
1 Check spark plug and spark (See page DI–63).
NG Go to step 4.
OK
2 Check for open and short in harness and connector in IGF and IGT signal circuitbetween ECM and ignition coil with igniter (See page IN–28).
NG Repair or replace harness or connector.
OK
3 Disconnect ignition coil with igniter connector and check voltage between termi-nals IGF of ECM connector and body ground.
PREPARATION:(a) Disconnect the ECM with connector from body panel
(See page SF–62).(b) Disconnect the ignition coil with igniter connector.(c) Turn the ignition switch ON.CHECK:Measure the voltage between terminals IGF of the ECM con-nector and body ground.OK:
Voltage: 4.5 – 5.5 V
OK Replace ignition coil with igniter.
NG
A12547
(+) (–)
IGT4 IGT3 IGT2 IGT1
A03401
IGT and IGFSsignal Waveforms5 V/Division
IGT
GND
IGF
GND
20 msec./ Division
DI–112–DIAGNOSTICS ENGINE
276Author: Date:
2000 MR2 (RM760U)
Check and replace ECM (See page IN–28).
4 Check for open and short in harness and connector in IGT signal circuit betweenECM and ignition coil with igniter (See page IN–28).
NG Repair or replace harness or connector.
OK
5 Check voltage between terminals IGT1 – IGT4 of ECM connector and bodyground.
PREPARATION:Disconnect the ECM with connector from body panel (See pageSF–62).CHECK:Measure the voltage between terminals IGT1 – IGT4 of theECM connector and body ground when the engine is cranked.OK:
Voltage: More than 0.1 V and less than 4.5 V
Reference: INSPECTION USING OSCILLOSCOPEDuring cranking or idling, check the waveform between termi-nals IGT1 – IGT4 and E1, IGF and E1 of the ECM connector.HINT:Correct waveform appears as shown, with rectangle waves.
NG Check and replace ECM (See page IN–28).
OK
A12547
(+) (–)
IGT4 IGT3 IGT2 IGT1
BE6653
A01761 A01861
ON
START1
(+)(–)
–DIAGNOSTICS ENGINEDI–113
277Author: Date:
2000 MR2 (RM760U)
6 Disconnect ignition coil with igniter connector and check voltage between termi-nals IGT1 – IGT4 of ECM connector and body ground.
PREPARATION:(a) Disconnect the ECM with connector from body panel
(See page SF–62).(b) Disconnect the ignition coil with igniter connector.CHECK:Measure the voltage between terminals IGT1 – IGT4 of theECM connector and body ground when the engine is cranked.OK:
Voltage: More than 0.1 V and less than 4.5 V
NG Check and replace ECM (See page IN–28).
OK
7 Check ignition coil with igniter power source circuit.
PREPARATION:Disconnect the ignition coil with igniter connector.CHECK:Measure the voltage between terminal 1 of the ignition coil withigniter connector and body ground when ignition switch isturned to ON and START position.OK:
Voltage: 9 – 14 V
NG Repair ignition coil with igniter power sourcecircuit.
OK
8 Check for open and short in harness and connector between ignition switch andignition coil with igniter (See page IN–28).
NG Repair or replace harness or connector.
OK
DI–114–DIAGNOSTICS ENGINE
278Author: Date:
2000 MR2 (RM760U)
9 Check IG2 relay (Marking: IG2) (See page IG–7).
NG Replace IG2 relay.
OK
Replace ignition coil with igniter.
–DIAGNOSTICS ENGINEDI–115
279Author: Date:
2000 MR2 (RM760U)
DTC P1335 Crankshaft Position Sensor Circuit Malfunc-tion (During engine running)
CIRCUIT DESCRIPTIONRefer to DTC P0335 on page DI–71.
DTC No. DTC Detection Condition Trouble Area
P1335
If conditions (a) through (c) are met:
(a) NE 1,000 rpm
(b) NE signal is not detected for over 50 msec.
(c) Not during cranking
Open or short in crankshaft position sensor circuit
Crankshaft position sensor
Crank angle sensor plate
ECM
WIRING DIAGRAMRefer to DTC P0335 on page DI–71.
INSPECTION PROCEDURERefer to DTC P0335 on page DI–71.
DI38K–03
DI–116–DIAGNOSTICS ENGINE
280Author: Date:
2000 MR2 (RM760U)
DTC P1346 VVT Sensor/Camshaft Position Sensor Cir-cuit Range/Performance Problem (Bank 1)
CIRCUIT DESCRIPTIONRefer to DTC P0335 on page DI–71.
DTC No. DTC Detection Condition Trouble Area
P1346Deviation in crankshaft position sensor signal and VVT sensor
(bank 1) signal (2 trip detection logic)
Mechanical system (Jumping teeth of timing chain, chain
stretched)
ECM
WIRING DIAGRAMRefer to DTC P0335 on page DI–71.
INSPECTION PROCEDUREHINT:Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze frame recordsthe engine conditions when the malfunction is detected. When troubleshooting, it is useful for determiningwhether the vehicle was running or stopped, the engine was warmed up or not, the air–fuel ratio was leanor rich, etc. at the time of the malfunction.
1 Check valve timing (Check for loose and jumping teeth of timing chain) (See page EM–13).
NG Adjust valve timing (Repair or replace timingchain).
OK
Check and replace ECM (See page IN–28).
DI7DG–01
A12069
C2OCV
1
2
R
ECM
OCV+
OCV–
24
23E5
E5
W
–DIAGNOSTICS ENGINEDI–117
281Author: Date:
2000 MR2 (RM760U)
DTC P1349 VVT System Malfunction (Bank 1)
CIRCUIT DESCRIPTIONVVT system controls the intake valve timing properly in response to driving condition.ECM controls OCV (Oil Control Valve) to make the intake valve timing properly, and, oil pressure controlledwith OCV is supplied to the VVT controller, and then, VVT controller changes relative position between thecamshaft and the crankshaft.
DTC No. DTC Detection Condition Trouble Area
P1349
Condition (a) or (b) continues for after the engine is warmed up
and engine speed at 400 – 4,000 rpm :
(a) Valve timing does not change from of current valve timing
(b) Current valve timing is fixed.
Valve timing
OCV
VVT controller assembly
ECM
WIRING DIAGRAM
INSPECTION PROCEDUREHINT: If DTC P1349 is displayed, check VVT system circuit. Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze frame
records the engine conditions when the malfunction is detected. When troubleshooting, it is useful fordetermining whether the vehicle was running or stopped, the engine was warmed up or not, the air–fuelratio was lean or rich, etc. at the time of the malfunction.
TOYOTA hand–held tester:
1 Check valve timing (See page EM–13).
NG Adjust valve timing.
OK
DI3HE–10
A02397
OCV Signal Waveform
1 msec./Division
5 V/Division
GND
(A) (A) (A)
DI–118–DIAGNOSTICS ENGINE
282Author: Date:
2000 MR2 (RM760U)
2 Check operation of OCV.
PREPARATION:(a) Start the engine and warm it up.(b) Connect the TOYOTA hand–held tester and select VVT from ACTIVE TEST menu.CHECK:Check the engine speed when operating the OCV by the TOYOTA hand–held tester.OK:
OCV is OFF: Normal engine speedOCV is ON: Rough idle or engine stall
OK VVT system is OK.*
*: DTC P1349 is also output after the foreign object is caughtin some part of the system in the engine oil and the system re-turns to normal in a short time. As ECM controls so that foreignobjects are ejected, there is no problem about VVT. There isalso no problem since the oil filter should get the foreign objectin the engine oil.
NG
3 Check voltage between terminals OCV+ and OCV– of ECM connector.
Reference: INSPECTION USING OSCILLOSCOPETurn the ignition switch ON, check waveform between terminalsOCV+ and OCV– of the ECM connector.HINT: The correct waveform is as shown. The waveform frequency (A) is lengthened as the engine
speed becomes higher.
NG Check and replace ECM (See page IN–28).
OK
4 Check VVT controller assembly (See page EM–33).
NG Replace VVT controller assembly, and then goto step NO TAG.
OK
–DIAGNOSTICS ENGINEDI–119
283Author: Date:
2000 MR2 (RM760U)
5 Check OCV (See page SF–43).
NG Replace OCV, and then go to step NO TAG.
OK
6 Check blockage of OCV, OCV valve and oil pipe No. 1.
NG Repair or replace.
OK
7 Check whether or not DTC P1349 is stored.
PREPARATION:(a) Clear the DTC (See page DI–3).(b) Perform simulation test.CHECK:Check whether or not DTC P1349 is stored (See page DI–3).OK:
DTC P1349 is not stored.
OK VVT system is OK.*
*: DTC P1349 is also output after the foreign object is caughtin some part of the system in the engine oil and the system re-turns to normal in a short time. As ECM controls so that foreignobjects are ejected, there is no problem about VVT. There isalso no problem since the oil filter should get the foreign objectin the engine oil.
NG
Check and replace ECM (See page IN–28).
OBD II scan tool (excluding TOYOTA hand–held tester):
1 Check valve timing (See page EM–13).
BE6653
A09089 A09103
A02397
OCV Signal Waveform
1 msec./Division
5 V/Division
GND
(A) (A) (A)
DI–120–DIAGNOSTICS ENGINE
284Author: Date:
2000 MR2 (RM760U)
NG Repair valve timing.
OK
2 Check operation of OCV.
PREPARATION:Start the engine.CHECK:(a) Check the engine speed when disconnecting the OCV
connector.(b) Check the engine speed when applying battery positive
voltage between terminals of OCV.RESULT:
Result Check (a) Check (b)
1 Normal engine speed Rough idle or engine stall
2 Except 1
2 Go to step NO TAG.
1
3 Check voltage between terminals OCV+ and OCV– of ECM connector.
Reference: INSPECTION USING OSCILLOSCOPETurn the ignition switch ON, check waveform between terminalsOCV+ and OCV– of the ECM connector.HINT: The correct waveform is as shown. The waveform frequency (A) is lengthened as the engine
speed becomes higher.
OK VVT system is OK.*
*: DTC P1349 is also output after the foreign object is caughtin some part of the system in the engine oil and the system re-turns to normal in a short time. As ECM controls so that foreignobjects are ejected, there is no problem about VVT. There isalso no problem since the oil filter should get the foreign objectin the engine oil.
NG
–DIAGNOSTICS ENGINEDI–121
285Author: Date:
2000 MR2 (RM760U)
Check and replace ECM (See page IN–28).
4 Check VVT controller assembly (See page EM–33).
NG Replace VVT controller assembly, and then goto step 5.
OK
5 Check OCV (See page SF–43).
NG Replace OCV, and then go to step 6.
OK
6 Check blockage of OCV, OCV and oil pipe No. 1.
NG Repair or replace.
OK
7 Check whether or not DTC P1349 is stored.
PREPARATION:(a) Clear the DTC (See page DI–3).(b) Perform simulation test.CHECK:Check whether or not DTC P1349 is stored (See page DI–3).OK:
DTC P1349 is not stored.
OK VVT system is OK.*
DI–122–DIAGNOSTICS ENGINE
286Author: Date:
2000 MR2 (RM760U)
*: DTC P1349 is also output after the foreign object is caughtin some part of the system in the engine oil and the system re-turns to normal in a short time. As ECM controls so that foreignobjects are ejected, there is no problem about VVT. There isalso no problem since the oil filter should get the foreign objectin the engine oil.
NG
Check and replace ECM (See page IN–28).
A13058
EFI1B–L
FL Block
B–YE2
FL Main
Battery
1
ECM
BATT1 1
1 2
BE6653
A09371
A12788
ON
BATT
(+) (–)
–DIAGNOSTICS ENGINEDI–123
287Author: Date:
2000 MR2 (RM760U)
DTC P1600 ECM BATT Malfunction
CIRCUIT DESCRIPTIONBattery positive voltage is supplied to terminal BATT of the ECM even when the ignition switch is OFF foruse by the DTC memory and air–fuel ratio adaptive control value memory, etc.
DTC No. DTC Detection Condition Trouble Area
P1600 Open in back up power source circuitOpen in back up power source circuit
ECM
HINT:If DTC P1600 appears, the ECM does not store another DTC.
WIRING DIAGRAM
INSPECTION PROCEDUREHINT:Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze frame recordsthe engine conditions when the malfunction is detected. When troubleshooting, it is useful for determiningwhether the vehicle was running or stopped, the engine was warmed up or not, the air–fuel ratio was leanor rich, etc. at the time of the malfunction.
1 Check voltage between terminal BATT of ECM connector and body ground.
PREPARATION:(a) Disconnect the ECM with connector from body panel
(See page SF–62).(b) Turn the ignition switch ON.CHECK:Measure the voltage between terminal BATT of the ECM con-nector and body ground.OK:
Voltage 9 – 14 V
DI38N–04
A12786
FL Block
EFI1 Fuse
DI–124–DIAGNOSTICS ENGINE
288Author: Date:
2000 MR2 (RM760U)
OK Check and replace ECM (See page IN–28).
NG
2 Check EFI1 fuse.
PREPARATION:Remove the EFI1 fuse from the fusible link block.CHECK:Check the continuity of the EFI1 fuse.OK:
Continuity
NG Check for short in all the harness and components connected to EFI1 fuse.
OK
Check and repair harness or connectorbetween battery and EFI1 fuse, EFI1 fuse andECM (See page IN–28).
A12895
C11
C10L
2IB1
6E2
10E3
1IB1 MPX1
MPX2
Combination Meter ECM
B
4
5
L
B
–DIAGNOSTICS ENGINEDI–125
289Author: Date:
2000 MR2 (RM760U)
DTC P1645 Body ECU Malfunction
CIRCUIT DESCRIPTIONThe ECM receives the operating condition (ON/OFF) of the A/C from the combination meter and it also re-ceives the electrical load information from the body ECU.The ECM uses the information to control the engine (idle up, etc.).
DTC No. DTC Detection Condition Trouble Area
P1645Condition below continues for 3.0 sec.
No communication from body ECU
Body ECU
A/C ECU
Vane pump assembly with motor
Air bag sensor assembly
ABS ECU
Communication bus
Combination meter
WIRING DIAGRAM
INSPECTION PROCEDUREHINT:Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze frame recordsthe engine conditions when the malfunction is detected. When troubleshooting, it is useful for determiningwhether the vehicle was running or stopped, the engine was warmed up or not, the air–fuel ratio was leanor rich, etc. at the time of the malfunction.
1 Check body ECU (See page DI–1).
NG Replace body ECU.
OK
DI7DH–01
DI–126–DIAGNOSTICS ENGINE
290Author: Date:
2000 MR2 (RM760U)
2 Check combination meter (See page BE–40).
NG Replace combination meter.
OK
3 Check harness and connector between combination meter and body ECU, ECMand combination meter (See page IN–28).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN–28).
–DIAGNOSTICS ENGINEDI–127
291Author: Date:
2000 MR2 (RM760U)
DTC P1656 OCV Circuit Malfunction (Bank 1)
CIRCUIT DESCRIPTIONRefer to DTC P1349 on page DI–117.
DTC No. DTC Detection Condition Trouble Area
P1656 Open or short in OCV circuit
Open or short in OCV circuit
OCV valve
ECM
WIRING DIAGRAMRefer to DTC P1349 on page DI–117.
INSPECTION PROCEDUREHINT:Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze frame recordsthe engine conditions when the malfunction is detected. When troubleshooting, it is useful for determiningwhether the vehicle was running or stopped, the engine was warmed up or not, the air–fuel ratio was leanor rich, etc. at the time of the malfunction.
TOYOTA hand–held tester:
1 Check OCV circuit.
PREPARATION:(a) Start the engine and warm it up.(b) Connect the TOYOTA hand–held tester and select VVT from the ACTIVE TEST menu.CHECK:Check the engine speed when operating the OCV by the TOYOTA hand–held tester.OK:
VVT system is OFF (OCV is OFF): Normal engine speedVVT system is ON (OCV is ON): Rough idle or engine stalled
OK Check for intermittent problems (See page DI–3).
NG
2 Check operation of OCV (See page DI–117).
NG Replace OCV.
OK
DI7DI–01
BE6653
A09089 A09103
START
DI–128–DIAGNOSTICS ENGINE
292Author: Date:
2000 MR2 (RM760U)
3 Check voltage between terminals OCV+ and OCV– of ECM connector (See pageDI–117, step 3).
NG Check and replace ECM (See page IN–28).
OK
4 Check for open and short in harness and connector between OCV and ECM (See page IN–28).
NG Repair or replace.
OK
Check for intermittent problems (See page DI–3).
OBD II scan tool (excluding TOYOTA hand–held tester):
1 Check operation of OCV.
PREPARATION:(a) Start the engine and warm it up.(b) Disconnect the OCV connector.(c) Apply battery positive voltage between the terminals of
the OCV.CHECK:Check the engine speed.OK:
Rough idle or engine stalled
NG Replace OCV.
OK
2 Check voltage between terminals OCV+ and OCV– of ECM connector (See pageDI–117, step 3).
–DIAGNOSTICS ENGINEDI–129
293Author: Date:
2000 MR2 (RM760U)
NG Check and replace ECM (See page IN–28).
OK
3 Check for open and short in harness and connector between OCV and ECM (See page IN–28).
NG Repair or replace.
OK
Check for intermittent problems (See page DI–3).
A13067
ECM
STPS7Stop Light Switch
R1Stop LightLH2
H4High MountedStop Light
21
2
R2Stop LightRH
1 2
2
E3
6G
BA1
IJ1G–W
J3D
J4F
W
STOP
B
W–B
EAED
6
R/B No. 3, J/B No. 3
3A 6
1
3
W–B W–B
GG
G
G G
G–W G
1
2
7J/C
FL Block
12
1
B–L
ALT
Battery FL Main
1
DI–130–DIAGNOSTICS ENGINE
294Author: Date:
2000 MR2 (RM760U)
Stop Light Switch Signal Circuit
CIRCUIT DESCRIPTIONThe purpose of this circuit is to prevent the engine from stalling, when brakes are suddenly applied. Whenthe brake pedal is depressed, this switch sends a signal to the ECM.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Check operation of stop light.
CHECK:Check if the stop lights go on and off normally when the brake pedal is depressed and released.
NG Check and repair stop light circuit.
OK
DI7DJ–01
Q06993
A11505
BE6653
A12744
ON
STP
Brake PedalDepressed
Brake PedalReleased
(+)(–)
–DIAGNOSTICS ENGINEDI–131
295Author: Date:
2000 MR2 (RM760U)
2 Check STP signal.
When using TOYOTA hand–held tester:PREPARATION:(a) Connect the TOYOTA hand–held tester to the DLC3.(b) Turn the ignition switch ON and push the TOYOTA hand–
held tester main switch ON.CHECK:Read the STP signal on the TOYOTA hand–held tester.OK:
Brake Pedal STP Signal
Depressed ON
Released OFF
When not using TOYOTA hand–held tester:PREPARATION:(a) Disconnect the ECM with connector from body panel
(See page SF–62).(b) Turn the ignition switch ON.CHECK:Measure the voltage between terminal STP of the ECM con-nector and body ground.OK:
Brake Pedal Voltage
Depressed 9.0 – 14 V
Released Below 1.5 V
OK Check for intermittent problems (See page DI–3).
NG
3 Check harness and connector between ECM and stop light switch (See page IN–18).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN–18).
A13049
ECM
+B
16
E2
B–R
Battery
W–R
GRMREL
21
E3
FL Main
EFI MAIN Relay
I10Ignition SW
EFI1
IGSW
6
IG2
IC1
35
2 1
10AM2R–W
E1
17
E4BR
EBEA
E2
BB–Y
8
35
2 1
2
2
2
2
2
2
2
2
1
1
1
1
1
1
1
2
2
2 5
2
W–B
W–B
W–R
R–W
B–W
B–L
IC1
Engine Room R/BFL Block
IG2 Relay
DI–132–DIAGNOSTICS ENGINE
296Author: Date:
2000 MR2 (RM760U)
ECM Power Source Circuit
CIRCUIT INSPECTIONWhen the ignition switch is turned on, battery positive voltage is applied to IG2 Relay, terminal IGSW of theECM and the EFI main relay (Marking: EFI MAIN) control circuit in the ECM sends a signal to terminal MRELof the ECM switching on the EFI main relay.This signal causes current to flow to the coil, closing the contacts of the EFI main relay and supplying powerto terminals +B of the ECM.If the ignition switch is turned off, the ECM continues to switch on the EFI main relay for a maximum of 2seconds for the initial setting of the IAC valve.
WIRING DIAGRAM
DI7DK–01
A09373
BE6653A10563
ON+B
E1 (–) (+)
A09636
BE6653
A09702
IGSW
(+)(–)
–DIAGNOSTICS ENGINEDI–133
297Author: Date:
2000 MR2 (RM760U)
INSPECTION PROCEDURE
1 Check voltage between terminals +B and E1 or ECM connectors.
PREPARATION:(a) Disconnect the ECM with connector from body panel
(See page SF–62).(b) Turn the ignition switch ON.CHECK:Measure the voltage between terminals +B and E1 of the ECMconnectors.OK:
Voltage: 9 – 14 V
OK Proceed to next circuit inspection shown onproblem symptoms table (See page DI–21).
NG
2 Check for open in harness and connector between terminal E1 of ECM connectorand body ground (See page IN–28).
NG Repair or replace harness or connector.
OK
3 Check voltage between terminal IGSW of ECM connector and body ground.
PREPARATION:(a) Disconnect the ECM with connector from body panel
(See page SF–62).(b) Turn the ignition switch ON.CHECK:Measure the voltage between terminal IGSW of the ECM con-nector and body ground.OK:
Voltage: 9 – 14 V
OK Go to step 6.
NG
A12786
FL Block
IG2 Fuse
A12786
FL Block
AM2 Fuse
DI–134–DIAGNOSTICS ENGINE
298Author: Date:
2000 MR2 (RM760U)
4 Check IG2 fuse.
PREPARATION:Remove the IG2 fuse from the FL block.CHECK:Check the continuity of the IG2 fuse.OK:
Continuity
NG Check for short in all harness and componentsconnected to IG2 fuse (See attached wiring dia-gram).
OK
5 Check IG2 relay (See page IG–7).
NG Replace IG2 relay.
OK
6 Check AM2 fuse.
PREPARATION:Remove the AM2 fuse from the FL block.CHECK:Check the continuity of the AM2 fuse.OK:
Continuity
NG Check for short in all harness and componentsconnected to AM2 fuse (See attached wiring dia-gram).
OK
BE6653
A09637
A09703
MREL
(+)(–)
–DIAGNOSTICS ENGINEDI–135
299Author: Date:
2000 MR2 (RM760U)
7 Check ignition switch (See page BE–15).
NG Replace ignition switch.
OK
Check and repair harness and connector be-tween battery and ignition switch, and igni-tion switch and ECM.
8 Check voltage between terminal MREL of ECM connector and body ground.
PREPARATION:(a) Disconnect the ECM with connector from body panel
(See page SF–62).(b) Turn the ignition switch ON.CHECK:Measure the voltage between terminal MREL of the ECM con-nector and body ground.OK:
Voltage: 9 – 14 V
NG Check and replace ECM (See page IN–28).
OK
9 Check EFI1 fuse (See page DI–123, step 2).
NG Check for short in all harness and componentsconnected to EFI1 fuse (See attached wiringdiagram).
OK
10 Check EFI main relay (Marking: EFI MAIN) (See page SF–44).
NG Replace EFI main relay.
DI–136–DIAGNOSTICS ENGINE
300Author: Date:
2000 MR2 (RM760U)
OK
11 Check for open and short in harness and connector between terminal MREL ofECM and body ground (See page IN–28).
NG Repair or replace harness or connector.
OK
Check and repair harness or connector be-tween EFI1 fuse and battery.
A13050
ECM
STAE3
11
Starter
ST Relay
MAIN
5
B–L
FL Main
1
2STAM2
W–R
I10 Ignition SW
Battery
FL
Blo
ck
B
C9Clutch StartSwitch
W–B
BI
R
7
IA1BC2 10
S2S1
1
1
1 11
1 11
11
22
11
1
2
W–R R
5
B–Y
L
B–L
4
7
3
1
2
B
B
B
10
B–Y
IC1IC1
11
–DIAGNOSTICS ENGINEDI–137
301Author: Date:
2000 MR2 (RM760U)
Starter Signal Circuit
CIRCUIT DESCRIPTIONWhen the engine is cranked, the intake air flow is slow, so fuel vaporization is poor. A rich mixture is thereforenecessary in order to achieve good startability. While the engine is being cranked, the battery voltage is ap-plied to terminal STA of the ECM. The starter signal is mainly used to increase the fuel injection volume forthe starting injection control and after–start injection control.
WIRING DIAGRAM
DI64N–03
DI–138–DIAGNOSTICS ENGINE
302Author: Date:
2000 MR2 (RM760U)
INSPECTION PROCEDUREHINT:This diagnostic chart is based on the premise that the engine is cranked normally. If the engine is notcranked, proceed to the problem symptoms table on page DI–21.
TOYOTA hand–held tester:
1 Check STA signal.
PREPARATION:(a) Connect the TOYOTA hand–held tester to the DLC3.(b) Turn the ignition switch ON and push the TOYOTA hand–held tester main switch ON.CHECK:Read the STA signal on the TOYOTA hand–held tester while the starter is operating.OK:
Ignition Switch Position ON START
STA Signal OFF ON
OK Proceed to next circuit inspection shown onproblem symptoms table (See page DI–21).
NG
2 Check for open in harness and connector between ECM and starter relay (Mark-ing: ST) (See page IN–28).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN–28).
BE6653
A11502
A12797
START
(+)(–)
STA
–DIAGNOSTICS ENGINEDI–139
303Author: Date:
2000 MR2 (RM760U)
OBD II scan tool (excluding TOYOTA hand–held tester):
1 Check voltage between terminal STA of ECM connector and body ground.
PREPARATION:(a) Disconnect the ECM with connector from body panel
(See page SF–62).(b) Turn the ignition switch ON.CHECK:Measure the voltage between terminal STA of the ECM connec-tor and body ground during the engine cranking.OK:
Voltage: 6 V or more
OK Proceed to next circuit inspection shown onproblem symptoms table (See page DI–21).
NG
2 Check for open in harness and connector between ECM and starter relay (Mark-ing: ST) (See page IN–28).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN–28).
A13062
Battery
MAIN
IG Switch
AM2
MAINFL
Starter
ClutchStartSwitch
ST Relay
Circuit Opening Relay
Fuel Pump
ECM
FC Tr
STA
NE
(NE Signal)
+B
A13052
ECM
FC3
E2
C/OPN Relay
4
F12Fuel Pump
2 B
Engine Room R/B
B–R
5
W–B
BK
R–W IC12
BA1
3
21
53
G–R2
2
2R–W
B–R
From Terminal 6 ofIgnition SW(See page DI–132)
FromTerminal 3 ofEFI MAIN Relay(See page DI–132)
DI–140–DIAGNOSTICS ENGINE
304Author: Date:
2000 MR2 (RM760U)
Fuel Pump Control Circuit
CIRCUIT DESCRIPTIONIn the diagram below, when the engine is cranked, current flows from terminal ST of the ignition switch tothe starter relay coil and also current flows to terminal STA of ECM (STA signal).When the STA signal and NE signal are input to the ECM, Tr is turned ON, current flows to coil of the circuitopening relay, the relay switches on, power is supplied to the fuel pump and the fuel pump operates.While the NE signal is generated (engine running), the ECM keeps Tr ON (circuit opening relay ON) and thefuel pump also keeps operating.
WIRING DIAGRAM
DI38Q–05
A09374BE6653
A12794
FCON
(–) (+)
–DIAGNOSTICS ENGINEDI–141
305Author: Date:
2000 MR2 (RM760U)
INSPECTION PROCEDURETOYOTA hand–held tester:
1 Connect TOYOTA hand–held tester and check operation of fuel pump (See pageDI–3).
OK Proceed to next circuit inspection shown onproblem symptoms table (See page DI–21).
NG
2 Check for ECM power source circuit (See page DI–132).
NG Repair or replace.
OK
3 Check circuit opening relay (Marking: C/OPN) (See page SF–47).
NG Replace circuit opening relay.
OK
4 Check voltage between terminal FC of ECM and body ground.
PREPARATION:(a) Disconnect the ECM with connector from body panel
(See page SF–62).(b) Turn the ignition switch ON.CHECK:Measure the voltage between terminal FC of the ECM and bodyground.OK:
Voltage: 9 – 14 V
OK Go to step 5.
NG
DI–142–DIAGNOSTICS ENGINE
306Author: Date:
2000 MR2 (RM760U)
Check for open in harness and connector between EFI main relay and circuit opening relay (Mark-ing: C/OPN), circuit opening relay and ECM (See page IN–28).
5 Check fuel pump (See page SF–7).
NG Repair or replace fuel pump.
OK
6 Check for open in harness and connector between circuit opening relay and fuelpump and body ground (See page IN–28).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN–28).
B10046
BE6653
A12795
ONFC
Fuel Inlet Hose
–DIAGNOSTICS ENGINEDI–143
307Author: Date:
2000 MR2 (RM760U)
OBD II scan tool (excluding TOYOTA hand–held tester):
1 Check operation of fuel pump.
PREPARATION:(a) Disconnect the ECM with connector from body panel
(See page SF–62).(b) Turn the ignition switch ON.CHECK:(a) Connect between terminal FC of the ECM connector and
body ground.(b) Check for fuel pressure in the fuel inlet hose when it is
pinched off.OK:
There is pressure in fuel inlet hose.HINT:At this time, you will hear a fuel return flowing noise.
OK Proceed to next circuit inspection shown onproblem symptoms table (See page DI–21).
NG
2 Check for ECM power source circuit (See page DI–132).
NG Repair or replace.
OK
3 Check circuit opening relay (Marking: C/OPN) (See page SF–47).
NG Replace circuit opening relay.
OK
DI–144–DIAGNOSTICS ENGINE
308Author: Date:
2000 MR2 (RM760U)
4 Check voltage between terminal FC of ECM and body ground (See page DI–140,step 4).
OK Go to step 5.
NG
Check for open in harness and connector between EFI main relay and circuit opening relay (Mark-ing: C/OPN), circuit opening relay and ECM (See page IN–28).
5 Check fuel pump (See page SF–7).
NG Repair or replace fuel pump.
OK
6 Check for open in harness and connector between circuit opening relay and fuelpump and body ground (See page IN–28).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN–28).
A13051
Com
bina
tion
Met
er
ECM
R/B No. 3,J/B No. 3
WBatteryE2
IG1 Relay
15Y–R
IC2
C10 17
C11
10
MIL
R–B
3
2153AB
IE
B–Y
10
W–B
Y–R3 3
3GAUGE
I10Ignition SW
2
1
1
1 2
12
3
1
1
1
2
FL Main
ALT
FL
Blo
ck
W–L
AM1
B–L
–DIAGNOSTICS ENGINEDI–145
309Author: Date:
2000 MR2 (RM760U)
MIL Circuit Malfunction
CIRCUIT DESCRIPTIONIf the ECM detects trouble, the MIL lights up. At this time, the ECM records a DTC in memory.
WIRING DIAGRAM
INSPECTION PROCEDUREHINT:Troubleshoot in accordance with the chart below for each trouble symptom.
MIL does not light up
Start inspection from step 1 in case of using TOYOTA hand–held
tester and start from step 2 in case of not using TOYOTA hand–
held tester
MIL remains on
After inspection of step 3, start inspection from step 4 in case of
using TOYOTA hand–held tester and start from step 5 in case of
not using TOYOTA hand–held tester
1 Inspect diagnosis (normal mode, check mode) (See page DI–3).
OK Check and replace ECM (See page IN–28).
NG
DI6MN–02
DI–146–DIAGNOSTICS ENGINE
310Author: Date:
2000 MR2 (RM760U)
2 Check MIL.
See combination meter troubleshooting on page BE–2.
NG Repair or replace bulb or combination meter as-sembly.
OK
3 Check that ECM connectors are securely connected to ECM.
NO Connect connector to ECM.
YES
Check for open circuit in harness and connector between combination meter and ECM (Seepage IN–28).
4 Check operation of MIL (See step 1).
OK Check and replace ECM (See page IN–28).
NG
5 Is any DTC output?
Check DTC on page DI–14.
YES Repair circuit indicated by output code.
NO
–DIAGNOSTICS ENGINEDI–147
311Author: Date:
2000 MR2 (RM760U)
6 Check IG1 relay (Marking: IG1) (See page BE–15).
NG Replace IG1 relay.
OK
Check for short circuit in harness and con-nector between DLC3 and ECM (See page IN–28).
A13060
IE
W–B
13TCE3TC
CG
D1DLC3
4
P–B2
J/B No. 6
526F6E IC2
3ECM
P–B P–B
F08565
CG
(–)
(+)
ON
TC
DI–148–DIAGNOSTICS ENGINE
312Author: Date:
2000 MR2 (RM760U)
TC Terminal Circuit
CIRCUIT DESCRIPTIONTerminal TC and CG are located in the DLC3. When connecting these terminals, DTCs in normal mode ortest mode can be read through the MIL flashing in the combination meter.
WIRING DIAGRAM
INSPECTION PROCEDUREHINT: Even though terminal TC is not connected with terminal CG, the MIL blinks. For the above phenomenon,an open or short in the wire harness, or malfunction inside the ECM is the
likely cause.
1 Check voltage between terminals TC and CG of DLC3.
PREPARATION:Turn the ignition switch ON.CHECK:Measure the voltage between terminals TC and CG of theDLC3.OK:
Voltage: 9 – 14 V
OK Check and replace ECM (See page IN–28).
NG
2 Check continuity between terminal CG of DLC3 and body ground.
DI7DL–01
–DIAGNOSTICS ENGINEDI–149
313Author: Date:
2000 MR2 (RM760U)
NG Repair or replace harness or connector.
OK
3 Check for open and short circuit in harness and connector between ECM andDLC3, and DLC3 and body ground (See page IN–28).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN–28).
A13053
ECM
A1A/C Magnetic Clutch andCompressor Lock Sensor
R–L
BC2 4
9 W–R
2 4
BR
EB
ACMG
LCK1
12E2
28E3W–R
R–L
B
1
2 2
2
2
Eng
ine
Roo
m R
/B
A/C
CO
MP
Rel
ay
PRE18E3
9W–L W–LW–B
BI
A11A/C Dual Pressure SW
1
2
5
3
4 1
BC2
IA1
R/B No. 3,J/B No. 3
Battery
IG1 Relay
3
2153A
B
IE
B–Y
W–B
3 3
3HTR
I10Ignition SW
2
1
1
1 2
12
3
1
1
1
2
FL Main
ALT
FL Block
W–L
AM1
B–L
DI–150–DIAGNOSTICS ENGINE
314Author: Date:
2000 MR2 (RM760U)
A/C Compressor Circuit
CIRCUIT DESCRIPTIONThis sensor sends 1 pulse par engine revolution to the ECM. If the number ratio of the compressor speeddivided by the engine speed is smaller than a predetermined value, the ECM turns the compressor off. And,the indicator flashes at about 1 second interval.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Check A/C compressor.
PREPARATION:(a) Check the tension of the compressor drive belt (See page AC–16).(b) Check if the compressor does not lock during operation with the engine started, and the blower switch
and A/C switch ON.
NG Adjust drive belt tension or repair compressor(See page AC–16).
DI7DM–01
N02774
LCKI Signal Waveform
20 msec./Division (Idling)
0 V
0.2
V/D
iv.
–DIAGNOSTICS ENGINEDI–151
315Author: Date:
2000 MR2 (RM760U)
OK
2 Check A/C compressor lock sensor (See page AC–46).
Reference: INSPECTION USING OSCILLOSCOPEDuring cranking or idling, check the waveform between termi-nals LCKI and E1 of the ECM connector.HINT:The correct waveform appears as shown.
NG Replace compressor lock sensor (See page AC–47).
OK
3 Check magnetic clutch relay (Marking: A/C COMP) (See page AC–71).
NG Replace magnetic clutch relay (See page AC–47).
OK
4 Check harness and connector between A/C compressor lock sensor and ECM(See page IN–28).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN–28).
DI7CJ–01
Vehicle Brought to Workshop
Customer Problem AnalysisP. DI–153
Check and Clear DTC (Pre–check)P. DI–154
Items inside are titles of pages in this manual,with the page number in the bottom portion. Seethe indicated pages for detailed explanations.
Problem Symptom Confirmation Symptom SimulationP. IN–18
Symptomdoes not occur
Symptomoccurs
DTC Check
Sensor CheckCircuit Inspection
P. DI–163 – DI–197
DTC ChartP. DI–158
Malfunction code
Problem Symptoms TableP. DI–162
Check for Fluid LeakageP. DI–199
Identification of Problem
Normal code
Repair
Confirmation Test
End
1
2
3 4
5
6 7
89
10
11
Step 2, 5, 8, 9, 11: Diagnostic steps permitting the use of theTOYOTA hand–held tester or TOYOTAbreak–out–box.
Fail safe function:When a failure occurs in the ABS system, the ABS warning light is lit and the ABS operation is prohibited.
P. DI–154
DI–152–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEM
316Author: Date:
2000 MR2 (RM760U)
ANTI–LOCK BRAKE SYSTEMHOW TO PROCEED WITH TROUBLESHOOTINGTroubleshoot in accordance with the procedure on the following pages.
DI7CK–01
ABS Check SheetInspector’sName :
Customer’s Name
Date VehicleBrought In
Registration Year
Registration No.
Frame No.
Odometer Reading
/ /
/ /
Date Problem First Occurred
Frequency Problem Occurs
/ /
Continuous Intermittent ( times a day)
Remains ON Does not Light Up
DTC Check
1st Time
2nd Time
Normal Code Malfunction Code (Code )
Normal Code Malfunction Code (Code )
Symptoms
kmmiles
ABS does not operate.
ABS Warning LightAbnormal
ABS does not operate efficiently.
–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEMDI–153
317Author: Date:
2000 MR2 (RM760U)
CUSTOMER PROBLEM ANALYSIS CHECK
F10852
DI7CL–01
A12716DLC3
4 (CG)
13 (Tc)
R01346
Normal Code
0.25 sec.
0.25 sec.
2 sec.
ON
OFF
ON
OFF
0.5 sec. 0.5 sec.
Codes 11 and 21
4 sec.
1.5 sec.
2.5 sec.
Code 11 Code 21
A12801
TOYOTAHand–held Tester
DLC3
DI–154–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEM
318Author: Date:
2000 MR2 (RM760U)
PRE–CHECK1. DIAGNOSIS SYSTEM(a) Check the warning light.
When the ignition switch is turned ON, check that the ABSwarning light go on for approx. 3 seconds.
HINT:If the indicator is not normal, proceed to troubleshooting for theABS warning light circuit (See page DI–192).
(b) In case of not using TOYOTA hand–held tester:Check the DTC.(1) Using SST, connect terminals Tc and CG of the
DLC3.SST 09843–18040(2) Turn the ignition switch ON.(3) Read the DTC from the ABS warning light on the
combination meter.
HINT: If no code appears, inspect the diagnostic circuit or ABS
warning light circuit (See page DI–195). As an example, the blinking patterns for normal code and
codes 11 and 21 are shown on the left.(4) Codes are explained in the code table on page
DI–158.(5) After completing the check, disconnect terminals Tc
and CG of the DLC3, and turn off the display.If 2 or more malfunctions are indicated at the same time, thelowest numbered DTC will be displayed first.
(c) In case of using TOYOTA hand–held tester:Check the DTC.(1) Hook up the TOYOTA hand–held tester to the
DLC3.(2) Turn the ignition switch ON.(3) Read the DTC by following the prompts on the tes-
ter screen.Please refer to the TOYOTA hand–held tester oper-ator’s manual for further details.
A12716DLC3
13 (Tc)
4 (CG)
BR3890
A12801
TOYOTAHand–held Tester
DLC3
N09348
Hand–held Tester
Break–out–box
ECU
TOYOTA
TOYOTA
–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEMDI–155
319Author: Date:
2000 MR2 (RM760U)
(d) In case of not using TOYOTA hand–held tester:Clear the DTC.(1) Using SST, connect terminals Tc and CG of the
DLC3.SST 09843–18040(2) Turn the ignition switch ON.
(3) Clear the DTC stored in ECU by depressing thebrake pedal 8 or more times within 5 seconds.
(4) Check that the warning light shows the normalcode.
(5) Remove the SST from the terminals of the DLC3.SST 09843–18040
(e) In case of using TOYOTA hand–held tester:Clear the DTC.(1) Hook up the TOYOTA hand–held tester to the
DLC3.(2) Turn the ignition switch ON.(3) Operate the TOYOTA hand–held tester to erase the
codes. (See hand–held tester oprater’s manual.)
(f) Reference:Using TOYOTA break–out–box and TOYOTA hand–heldtester, measure the ECU terminal values.(1) Hook up the TOYOTA hand–held tester and
TOYOTA break–out–box to the vehicle.(2) Read the ECU input/output values by following the
prompts on the tester screen.HINT:TOYOTA hand–held tester has a ”Snapshot” function. This re-cords the measured values and is effective in the diagnosis ofintermittent problems.Please refer to the TOYOTA hand–held tester/TOYOTA break–out–box operator’s manual for further details.
F11790DLC3
14 (Ts)
13 (Tc)
4 (CG)
BR3893
F10845
F11867
7 2 67
ON
OFF
0.5 sec.0.5 sec.0.5 sec.0.5 sec.
1.5 sec. 2.5 sec. 4 sec.
RepeatCode 72 Code 76
ON
OFF 0.25 sec.0.25 sec.
2 sec.
Normal Code
Malfunction Code (Example Code 72, 76)A Cycle
DI–156–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEM
320Author: Date:
2000 MR2 (RM760U)
2. SPEED SENSOR SIGNAL (TEST MODE)(a) In case of not using TOYOTA hand–held tester:
Check the speed sensor signal.(1) Turn the ignition switch OFF.(2) Using SST, connect terminals Ts and CG of the
DLC3.SST 09843–18040(3) Start the engine.(4) Check that the ABS warning light blinks.
HINT:If the ABS warning light does not blink, inspect the ABS warninglight circuit (See page DI–192).
(5) Drive vehicle straight forward.HINT:Drive vehicle at faster than 45 km/h (28 mph) for several se-conds.
(6) Stop the vehicle.(7) Using SST, connect terminals Tc and CG of the
DLC3.SST 09843–18040(8) Read the number of blinks of the ABS warning light.
HINT: See the list of DTC shown on the next page. If each sensor is normal, a normal code is output (A cycle
of 0.25 sec. ON and 0.25 sec. OFF is repeated). If 2 or more malfunctions are indicated at the same time,
the lowest numbered code will be displayed first.
(9) After doing the check, disconnect the SST from ter-minals Ts, Tc and CG of the DLC3, and turn ignitionswitch OFF.
SST 09843–18040
A12801
TOYOTAHand–held Tester
DLC3
–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEMDI–157
321Author: Date:
2000 MR2 (RM760U)
(b) Using TOYOTA hand–held tester:Check the DTC.(1) Hook up the TOYOTA hand–held tester to the
DLC3.(2) Do steps (3) to (6) on the previous page and this
page.(3) Read the DTC by following the prompts on the tes-
ter screen.Please refer to the TOYOTA hand–held tester oper-ator’s manual for further details.
DTC of speed sensor check function:
Code No. Diagnosis Trouble Area
C1271/71 Low output voltage of right front speed sensor
Right front speed sensor
Sensor installation
Right front speed sensor rotor
C1272/72 Low output voltage of left front speed sensor
Left front speed sensor
Sensor installation
Left front speed sensor rotor
C1273/73 Low output voltage of right rear speed sensor
Right rear speed sensor
Sensor installation
Right rear speed sensor rotor
C1274/74 Low output voltage of left rear speed sensor
Left rear speed sensor
Sensor installation
Left rear speed sensor rotor
C1275/75Abnormal change in output voltage of right front speed sen-
sorRight front speed sensor rotor
C1276/76Abnormal change in output voltage of left front speed
sensorLeft front speed sensor rotor
C1277/77Abnormal change in output voltage of right rear speed
sensorRight rear speed sensor rotor
C1278/78 Abnormal change in output voltage of left rear speed sensor Left rear speed sensor rotor
DI7CM–01
DI–158–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEM
322Author: Date:
2000 MR2 (RM760U)
DIAGNOSTIC TROUBLE CODE CHARTHINT: Using SST 09843–18040, connect terminals Tc and CG of the DLC3. If any abnormality is not found in inspection parts, inspect the ECU. If a malfunction code is displayed during the DTC check, check the circuit listed for the code. For details
of each code, turn to the page referred to under the ”See page” for respective ”DTC No.” in the DTCchart.
DTC No.
(See page)Detection Item Trouble Area
C0278/11
(DI–178)Open circuit in ABS solenoid relay circuit
ABS solenoid relay
C0279/12
(DI–178)Short circuit in ABS solenoid relay circuit
ABS solenoid relay
ABS solenoid relay circuit
C0273/13
(DI–173)Open circuit in ABS motor relay circuit
ABS motor relay
C0274/14
(DI–173)Short circuit in ABS motor relay circuit
ABS motor relay
ABS motor relay circuit
C0226/21
(DI–170)
Open or short circuit in 2–position solenoid circuit for right front
wheel
ABS actuator
SFRR or SFRH circuit
C0236/22
(DI–170)
Open or short circuit in 2–position solenoid circuit for left front
wheel
ABS actuator
SFLR or SFLH circuit
C0246/23
(DI–170)
Open or short circuit in 2–position solenoid circuit for right rear
wheel
ABS actuator
SRRR or SRRH circuit
C0256/24
(DI–170)
Open or short circuit in 2–position solenoid circuit for left rear
wheel
ABS actuator
SRLR or SRLH circuit
C0200/31
(DI–163)Right front wheel speed sensor signal malfunction
Right front, left front, right rear or left rear speed sensor
E h d i itC0205/32
(DI–163)Left front wheel speed sensor signal malfunction
Each speed sensor circuit
Speed sensor rotor
C0210/33
(DI–163)Right rear wheel speed sensor signal malfunction Rear axle hub
Right rear or left rear speed sensor
C0215/34
(DI–163)Left rear wheel speed sensor signal malfunction
Right rear or left rear s eed sensor
Each speed sensor circuit
Speed sensor rotor
C1235/35
(DI–163)Foreign matter is attached on the tip of the right front sensor
C1236/36
(DI–163)Foreign matter is attached on the tip of the left front sensor
Right front, left front, right rear or left rear speed sensor
E h d i itC1238/38
(DI–163)Foreign matter is attached on the tip of the right rear sensor
Each speed sensor circuit
Speed sensor rotor
C1239/39
(DI–163)Foreign matter is attached on the tip of the left rear sensor
C1241/41
(DI–183)Power source voltage down
Battery
Charging system
Power source circuit
C1249/49
(DI–186)Open circuit in stop light switch circuit
Stop light switch
Stop light switch circuit
–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEMDI–159
323Author: Date:
2000 MR2 (RM760U)
C1251/51
(DI–188)Pump motor is locked ABS pump motor
Always ON
(DI–190)Malfunction in ECU
Charging system
ABS warning light circuit
Battery
ABS ECU
DI7CN–01
F10848
Sensor Rotor
ABS Warning Light
ABS ECU
ABS Actuator
ABS Solenoid Relay(Marking: ABS SOL Relay)
Stop Light Switch
DLC3
R/B No. 4
Parking Brake Switch
Stop LightABS Motor Relay(Marking: ABS MTR Relay)
Front Speed Sensor(with Rotor)
Front Speed Sensor(with Rotor)
Combination Meter
High Mounted Stop LightRear Speed Sensor
FL Block
R/B No. 3
J/B No. 6
DI–160–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEM
324Author: Date:
2000 MR2 (RM760U)
PARTS LOCATION
DI7CO–01
F07155
A6 A7
12348 567910111213
141516171819202122
123456
789101112 23242526
–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEMDI–161
325Author: Date:
2000 MR2 (RM760U)
TERMINALS OF ECU
Symbols (Terminal No.) Wiring Color Condition STD Voltage (V)
IG1 (A7–13) –
GND (A7–12, 25)B–R ↔ W–B IG switch ON 10 – 14
R+ (A7–26) – SR (A6–7) L ↔ R–B IG switch ON, ABS warning light OFF 9 – 14
R+ (A7–26) – MR (A6–1) L ↔ R–Y IG switch ON Below 1.0
SFRR (A7–1) –
GND (A7–12, 25)W–L ↔ W–B IG switch ON, ABS warning light OFF 10 – 14
SFRH (A7–2) –
GND (A7–12, 25)W–G ↔ W–B IG switch ON, ABS warning light OFF 10 – 14
SFLR (A6–6) –
GND (A7–12, 25)W ↔ W–B IG switch ON, ABS warning light OFF 10 – 14
SFLH (A6–5) –
GND (A7–12, 25)W–R ↔ W–B IG switch ON, ABS warning light OFF 10 – 14
SRRR (A7–12) –
GND (A7–12, 25)R–G ↔ W–B IG switch ON, ABS warning light OFF 10 – 14
SRRH (A6–11) –
GND (A7–12, 25)R–B ↔ W–B IG switch ON, ABS warning light OFF 10 – 14
SRLR (A7–14) –
GND (A7–12, 25)R–W ↔ W–B IG switch ON, ABS warning light OFF 10 – 14
SRLH (A7–15) –
GND (A7–12, 25)R–L ↔ W–B IG switch ON, ABS warning light OFF 10 – 14
WA (A7 11) GND (A7 12 25) R G W BIG switch ON, ABS warning light ON 10 – 14
WA (A7–11) – GND (A7–12, 25) R–G ↔ W–BIG switch ON, ABS warning light OFF Below 2.0
STP (A7 5) GND (A7 12 25) G W W BStop light switch OFF Below 1.5
STP (A7–5) – GND (A7–12, 25) G–W ↔ W–BStop light switch ON 8 – 14
D/G (A7–24) –
GND (A7–12, 25)W–G ↔ W–B IG switch ON, ABS warning light OFF 10 – 14
Tc (A7–8) – GND (A7–12, 25) P–B ↔ W–B IG switch ON 8 – 14
Ts (A7–21) – GND (A7–12, 25) G–R ↔ W–B IG switch ON 8 – 14
FR+ (A6–3) – FR– (A6–9) R ↔ G IG switch ON, Slowly turning right front wheel AC generation
FL+ (A6–8) – FL– (A6–2) L ↔ P IG switch ON, Slowly turning left front wheel AC generation
RR+ (A7–10) – RR– (A7–23) B ↔ W IG switch ON, Slowly turning right rear wheel AC generation
RL+ (A7–22) – RL– (A7–9) Y ↔ BR IG switch ON, Slowly turning left rear wheel AC generation
MT (A6–10) – GND (A7–12, 25) L–W ↔ W–B IG switch ON Below 1.5
DI7CP–01
DI–162–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEM
326Author: Date:
2000 MR2 (RM760U)
PROBLEM SYMPTOMS TABLEIf a normal code is displayed during the DTC check but the problem still occurs, check the circuits for eachproblem symptom in the order given in the table below and proceed to the relevant troubleshooting page.NOTICE:When replacing ABS ECU, sensor or etc., turn the IG switch OFF.
Symptom Suspected Area See page
ABS does not operate
Only when 1. to 4. are all normal and the problem is still
occurring, replace the ABS ECU.
3. Check the DTC reconfirming that the normal code is
output.
4. IG power source circuit
5. Speed sensor circuit
6. Check the ABS actuator with a checker or TOYOTA
hand–held tester.
If abnormal, check the hydraulic circuit for leakage
(See page DI–199).
DI–154
DI–183
DI–163
BR–42
ABS does not operate efficiently
Only when 1. to 4. are all normal and the problem is still
occurring, replace the ABS ECU.
1. Check the DTC reconfirming that the normal code is
output.
2. Speed sensor circuit
3. Stop light switch circuit
4. Check the ABS actuator with a checker or TOYOTA
hand–held tester.
If abnormal, check the hydraulic circuit for leakage
(See page DI–199).
DI–154
DI–163
DI–186
BR–42
ABS warning light abnormal1. ABS warning light circuit
2. ABS ECU
DI–192
DTC check cannot be done
Only when 1. and 2. are all normal and the problem is still
occurring, replace the ABS ECU.
1. ABS warning light circuit
2. Tc terminal circuit
DI–192
DI–195
Speed sensor signal check cannot be done1. Ts terminal circuit
2. ABS ECU
DI–197
DI7CQ–01
BR3583BR3582 F00010
RotorSpeed Sensor
Magnet
To ECU
+V
–V
High Speed
Low Speed
Coil
N S
–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEMDI–163
327Author: Date:
2000 MR2 (RM760U)
CIRCUIT INSPECTION
DTC C0200/31 – C1239/39 Speed Sensor Circuit
CIRCUIT DESCRIPTIONThe speed sensor detects wheel speed and sends the ap-propriate signals to the ECU. These signals are used to controlthe ABS system. The front and rear rotors each have 48 serra-tions.When the rotors rotate, the magnetic field emitted by the perma-nent magnet in the speed sensor generates an AC voltage.Since the frequency of this AC voltage changes in direct propor-tion to the speed of the rotor, the frequency is used by the ECUto detect the speed of each wheel.
DTC No. DTC Detection Condition Trouble Area
C0200/31
C0205/32
C0210/33
C0215/34
Detection of any of conditions from 1. through 3.:
1. Vehicle speed is at 10 km/h (6 mph) or more and open
or short of the speed sensor signal circuit continues 15
sec. or more.
2. Momentary interruption of the speed sensor signal oc-
curs 7 times or more.
3. Open circuit condition of the speed sensor signal circuit
continues for 0.5 sec. or more.
Right front, left front, right rear or left rear speed sensor
Each speed sensor circuit
Speed sensor rotor
C1235/35
C1236/36
C1238/38
C1239/39
Vehicle speed is at 20 km/h (12mph) or more and interfer-
ence on the speed sensor signal continues for 5 sec. or
more.
Right front, left front, right rear or left rear speed sensor
Each speed sensor circuit
Speed sensor rotor
C0210/33
C0215/34
The condition that the both rear side wheels’ speed is lower
than the front wheels’ speed at 20 km/h (12 mph) or more
for 20 sec. or more when the IG switch turns ON and OFF,
which is repeated in a sequence more than 8 times.
Rear axle hub
Right rear or left rear speed sensor
Rear speed sensor circuit
HINT: DTC Nos. C0200/31 and C1235/35 are for the right front speed sensor. DTC Nos. C0205/32 and C1236/36 are for the left front speed sensor. DTC Nos. C0210/33 and C1238/38 are for the right rear speed sensor. DTC Nos. C0215/34 and C1239/39 are for the left rear speed sensor.
F11488
ABS ECU
FR+
FR–
FL+
FL–
RR+
RR–
RL+
RL–
A3Right Rear Speed Sensor
A15Right Front Speed Sensor
A14Left Front Speed Sensor
A2Left Rear Speed Sensor
2
1
2
1
A6
W
B
2
8
1
1
2
2
B
W
A6
A6
A6
A7
A7
A7
A7
3
9
22
9
10
23
BR
14
7
IC3
IJ113
6
7
Y
BR
Y
R
G
R
G
L L
2
P
IG2
IG2
IG2
3
4P
IG2
IC3
IJ1
DI–164–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEM
328Author: Date:
2000 MR2 (RM760U)
WIRING DIAGRAM
F10179
1
2
–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEMDI–165
329Author: Date:
2000 MR2 (RM760U)
INSPECTION PROCEDUREHINT:Start the inspection from step 1 in case of using the TOYOTA hand–held tester and start from step 2 in caseof not using the TOYOTA hand–held tester.
1 Check output value of speed sensor.
PREPARATION:(a) Connect the TOYOTA hand–held tester to the DLC3.(b) Turn the ignition switch ON and push the TOYOTA hand–held tester main switch ON.(c) Select the DATALIST mode on the TOYOTA hand–held tester.CHECK:Check that there is no difference between the speed value output from the speed sensor displayed on theTOYOTA hand–held tester and the speed value displayed on the speedometer when driving the vehicle.OK:
There is almost no difference from the displayed speed value.HINT:There is tolerance of ± 10 % in the speedometer indication.
OK Check and replace ABS ECU.
NG
2 Check speed sensor.
Front speed sensor:PREPARATION:(a) Make sure that there is no looseness at the connector
lock part and connecting part of the connector.(b) Disconnect the speed sensor connector at hub bearing.CHECK:Measure the resistance between terminals 1 and 2 of the speedsensor connector.OK:
Resistance: 1.1 – 1.3 k Ω at 25°CCHECK:Measure the resistance between terminals 1 and 2 of the speedsensor connector and body ground.OK:
Resistance: 1 M Ω or higher
F11771
12
F11762
1
2
Connector 1
Connector 221
RH
1
2
Connector 1
Connector 22 1
LH
DI–166–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEM
330Author: Date:
2000 MR2 (RM760U)
Rear speed sesor:PREPARATION:(a) Make sure the that there is no looseness at the connector
lock part and connecting part of the connector.(b) Disconnect the speed sensor connector.CHECK:Measure the resistance between terminals 1 and 2 of the speedsensor connector.OK:
Resistance: 0.9 – 1.3 k Ω at 25 ± 5 °CCHECK:Measure the resistance between terminals 1 and 2 of the speedsensor connector and body ground.OK:
Resistance: 10 M Ω or higherFront speed sensor sub–wire:PREPARATION:(a) Remove the fender liner.(b) Make sure that there is no looseness at the connector
lock part and connecting part of the connector.(c) Disconnect the speed sensor connector inside vehicle.CHECK:(a) Measure the resistance between terminal 1 of connector
1 and terninal 2 of connector 2.(b) Measure the resistance between terminal 2 of connector
1 and terninal 1 of connector 2.OK:
Resistance: below 1 ΩCHECK:Measure the resistance between terminals 1 and 2 of connector1 and body ground.OK:
Resistance: 10 M Ω or higher
NG Replace speed sensor or sub–wire harness.
NOTICE:Check the speed sensor signal last (See page DI–154).
OK
BR3795
F10178
F11797
Front
Rear
OK
NGOK
NG
–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEMDI–167
331Author: Date:
2000 MR2 (RM760U)
3 Check for open and short circuit in harness and connector between each speedsensor and ABS ECU (See page IN–28).
NG Repair or replace harness or connector.
OK
4 Check speed sensor installation.
CHECK:Check the speed sensor installation.OK:
The installation bolt is tightened properly and there isno clearance between the sensor and steeringknuckle or rear axle carrier.
NG Replace speed sensor.
NOTICE:Check the speed sensor signal last (See page DI–154).
OK
W04200
Normal Signal Waveform
1 V/Division2 m/s/Division
GND
W04846
DI–168–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEM
332Author: Date:
2000 MR2 (RM760U)
5 Check speed sensor and sensor rotor serrations.
REFERENCE: INSPECTION USING OSCILLOSCOPEPREPARATION:(a) Remove the ABS ECU with the connectors still con-
nected.(b) Connect the oscilloscope to terminals FR+, FL+, RR+ or
RL+ and GND of the ABS ECU.CHECK:Drive the vehicle at about 30 km/h (19 mph), and check the sig-nal waveform.
OK Check and replace ABS ECU.
NG
6 Check sensor rotor and sensor tip.
Front:PREPARATION:Remove the front speed sensor (See page BR–51).CHECK:Check the sensor rotor serrations.OK:
No scratches or missing teeth or foreign objects.CHECK:Check the sensor tip.OK:
No scratches or foreign objects on the sensor tip.
R00948
–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEMDI–169
333Author: Date:
2000 MR2 (RM760U)
Rear:PREPARATION:Remove the rear drive shaft (See page SA–41).CHECK:Check the sensor rotor serrations.OK:
No scratches or missing teeth or foreign objects.PREPARATION:Remove the rear speed sensor (See page BR–56).CHECK:Check the sensor tip.OK:
No scratches or foreign objects on the sensor tip.
NG Replace sensor rotor or speed sensor.
NOTICE:Check the speed sensor signal last (See page DI–154).
OK
Check and replace ABS ECU.
DI–170–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEM
334Author: Date:
2000 MR2 (RM760U)
DTC C0226/21 – C0256/24 ABS Actuator Solenoid Circuit
CIRCUIT DESCRIPTIONThis solenoid goes on when signals are received from the ECU and controls the pressure acting on the wheelcylinders thus controlling the braking force.
DTC No. DTC Detection Condition Trouble Area
C0226/21
Condition 1. or 2. continues for 0.05 sec. or more:
1. IG1 terminal voltage of ABS ECU is 9.5 – 18.5 V, there
is open or short circuit in actuator solenoid SFRR or
SFRH.
2. IG1 terminal voltage of ABS ECU is 9.5 – 18.5 V, and
while ABS control is in operation.*
ABS actuator
SFRR or SFRH circuit
C0236/22
Condition 1. or 2. continues for 0.05 sec. or more:
1. IG1 terminal voltage of ABS ECU is 9.5 – 18.5 V, there
is open or short circuit in actuator solenoid SFLR or
SFLH.
2. IG1 terminal voltage of ABS ECU is 9.5 – 18.5 V, and
while ABS control is in operation.*
ABS actuator
SFLR or SFLH circuit
C0246/23
Condition 1. or 2. continues for 0.05 sec. or more:
1. IG1 terminal voltage of ABS ECU is 9.5 – 18.5 V, there
is open or short circuit in actuator solenoid SRRR or
SRRH.
2. IG1 terminal voltage of ABS ECU is 9.5 – 18.5 V, and
while ABS control is in operation.*
ABS actuator
SRRR or SRRH circuit
C0256/24
Condition 1. or 2. continues for 0.05 sec. or more:
1. IG1 terminal voltage of ABS ECU is 9.5 – 18.5 V, there
is open or short circuit in actuator solenoid SRLR or
SRLH.
2. IG1 terminal voltage of ABS ECU is 9.5 – 18.5 V, and
while ABS control is in operation.*
ABS actuator
SRLR or SRLH circuit
*: Solenoid relay contact ON condition:All of solenoid terminal voltage is half or less than IG1 terminal voltage .
DI7CR–01
F11490
26A7 R+
7A6 SR
15A7
A714
A6
A6
A6
A7
A7
A7
5
6
11
12
2
1
SRLH
SRLR
SFLH
SFLR
SRRH
SRRR
SFRH
SFRR
W
W–L
BS
W–R
W–B
R–L
R–W
1A
4
R–B
R–G
W–G
GND
GND
A7
A7
12
25W–B
A13
A12
A12
A12
A12
A12
A12
A12
A12
2
6
3
7
8
1
5
SFLH
SFLR
SRRH
SRRR
4
1
5 3
2
ABS SOL Relay
R/B No. 4, J/B No. 4
FL Main
Battery
ALT
IF210
FL Block, J/B No. 1
B–L
IA2
1
1
1
2
ABS Actuator
J2 J/CA
10
11
4
5
IH
ABS ECU
IF1
IF1
IF1
IF1
7
8
9
6
W
W–R
R–B
R–G
L L
IF24
4
4
4
4 4A1
R–B9
1B
L–B
R–L
H1
H1
IF1
IF1
W–L
R–W
W–G
SRLH
SRLR
SFRH
SFRR
A
A
ABS1B–GR
R–B
W–B
2 1
–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEMDI–171
335Author: Date:
2000 MR2 (RM760U)
WIRING DIAGRAM
W00714
1234
5678
4
1234
5678
4
1234
5678
4
1234
5678
4
1234
5678
4
A121
234
5678
4
A13
DI–172–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEM
336Author: Date:
2000 MR2 (RM760U)
INSPECTION PROCEDURE
1 Check ABS actuator solenoid.
PREPARATION:Disconnect the 2 connectors from the ABS actuator.CHECK:Check the continuity between terminals A13–4 and A12–1, 2,3, 4, 5, 6, 7, 8 of the ABS actuator connector.OK:
ContinuityHINT:Resistance of each solenoid coilSRLR, SRRR, SFLR, SFRR: 4.3 ΩSRLH, SRRH, SFLH, SFRH: 8.8 Ω
NG Replace ABS actuator.
OK
2 Check for open and short circuit in harness and connector between ABS ECU
and actuator (See page IN–28).
NG Repair or replace harness or connector.
OK
If same code is still output after DTC is deleted, check connections. If connections are normal,ECU may be defective.
–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEMDI–173
337Author: Date:
2000 MR2 (RM760U)
DTC C0273/13, C0274/14 ABS Motor Relay Circuit
CIRCUIT DESCRIPTIONThe ABS motor relay (Marking: ABS MTR) supplies power to the ABS pump motor. While the ABS is acti-vated, the ECU switches the ABS motor relay ON and operates the ABS pump motor.
DTC No. DTC Detection Condition Trouble Area
C0273/13
Condition 1. or 2. continues for 0.2 sec. or more:
1. ABS ECU terminal IG1 voltage is 9.5 V to 18.5 V, and
when motor relay is ON in the midst of initial check or
when ABS control is in operation.*1
2. Motor relay is ON driving in the midst of initial check or
when ABS control is in operation, ABS ECU terminal
IG1 voltage becomes 9.5 V or less.*2
ABS motor relay
ABS motor relay circuit
C0274/14
Condition below continues for 4 sec. or more:
When the motor relay is OFF, there is open circuit in MT
terminal of ABS ECU.
*1: Relay contact OFF condition: MT terminal voltage is below 3.6 V.*2: Relay contact ON condition: MT terminal voltage is 3.6 V or above.
DI7CS–01
F11492
FL Main
Battery
ABS ECU
GND
AW–B
3A13
10MT
A13
A13
12
25GND
2
1
GND
MT
BM
W–B
W–BJ2J/C
26A7 R+
7A6 SR
1
5 3
2
10L L
4
4
4
4
4 4A1
R–B
1B
L
ABS2
B–GR
R–Y
1A
ALT
B–L
1
1
1
2
A7
A6
A
A
BL BM
W–B
12
A7
W–B
W–B
L–W
IF2
IF29
ABS SOL Relay
2 1
IA2
IH
L–W IF1
R/B No. 4, J/B No. 4
ABS Actuator
FL Block, J/B No. 1
DI–174–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEM
338Author: Date:
2000 MR2 (RM760U)
WIRING DIAGRAM
F10858
R/B No. 4LOCK5
(+)(–)
–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEMDI–175
339Author: Date:
2000 MR2 (RM760U)
INSPECTION PROCEDUREHINT:Start the inspection from step 1 in case of using the TOYOTA hand–held tester and start from step 2 in caseof not using TOYOTA hand–held tester.
1 Check ABS motor relay (Marking: ABS MTR) operation.
PREPARATION:(a) Connect the TOYOTA hand–held tester to the DLC3.(b) Turn the ignition switch ON and push the TOYOTA hand–held tester main switch ON.(c) Select the ACTIVE TEST mode on the TOYOTA hand–held tester.CHECK:Check the operation sound of the ABS motor relay when operating it with the TOYOTA hand–held tester.OK:
The operation sound of the ABS motor relay should be heard.
OK Go to step 5.
NG
2 Check voltage between terminal 5 of R/B No. 4 (for ABS motor relay (Marking:ABS MTR)) and body ground.
PREPARATION:Remove the ABS motor relay from the R/B No. 4.CHECK:Measure the voltage between terminal 5 of the R/B No. 4 (forABS motor relay) and body ground.OK:
Voltage: 10 – 14 V
NG Check and repair harness or connector be-tween R/B No. 4 and battery.
OK
F09762
ABSMotorRelay
ABSECU
10
ABS Actuator
3
22
33
A6
A13
A13
R/B No. 4
DI–176–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEM
340Author: Date:
2000 MR2 (RM760U)
3 Check continuity between terminal 3 of R/B No. 4 (for ABS motor relay (Marking:ABS MTR)) and terminal MT (A6–10) of ABS ECU.
CHECK:Check the continuity between terminal 3 of the R/B No. 4 (forABS motor relay) and terminal MT (A6–10) of the ABS ECU.OK:
ContinuityHINT:There is a resistance of 4 – 6 Ω between terminals A13–2 andA12–3 of the ABS actuator.
NG Repair or replace harness or ABS actuator.
OK
F09763
BE1840
F11853
5
Continuity
Open
3
21
2 5
1
3
Continuity
2
1
3
5
–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEMDI–177
341Author: Date:
2000 MR2 (RM760U)
4 Check ABS motor relay (Marking: ABS MTR).
PREPARATION:Remove the ABS motor relay from the R/B No. 4.CHECK:Check the continuity between each terminal of the ABS motorrelay.OK:
Terminals 1 and 2 Continuity (Reference value 62 Ω)
Terminals 3 and 5 Open
CHECK:(a) Apply battery positive voltage between terminals 1 and 2.(b) Check the continuity between terminals of the ABS motor
relay.OK:
Terminals 3 and 5 Continuity
NG Replace ABS motor relay.
OK
5 Check for open and short circuit in harness and connector between ABS motorrelay (Marking: ABS MTR) and ABS ECU (See page IN–28).
NG Repair or replace harness or connector.
OK
If same code is still output after the DTC is deleted, check connections. If connections are normal,ECU may be defective.
DI–178–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEM
342Author: Date:
2000 MR2 (RM760U)
DTC C0278/11, C0279/12 ABS Solenoid Relay Circuit
CIRCUIT DESCRIPTIONThis ABS solenoid relay (Marking: ABS SOL) supplies power to each ABS solenoid. After the ignition switchis turned ON, if the initial check is OK, the relay goes on.
DTC No. DTC Detection Condition Trouble Area
C0278/11
Condition 1. or 2. continues for 0.2 sec. or more:
1. IG1 terminal voltage of ABS ECU is 9.5 – 18.5 V, and
when the solenoid relay is ON.*1
2. With solenoid relay ON, when IG1 terminal of ABS ECU
is less than 9.5 V.*1
ABS solenoid relay
ABS solenoid relay circuit
C0279/12Immediately after IG switch has been turned ON, when the
solenoid relay is OFF.*2
*1: Solenoid relay contact OFF condition:All of solenoid terminal voltage is half or less than IG1 terminal voltage.*2: Solenoid relay contact ON condition:All of solenoid terminal voltage is half of IG1 terminal voltage or more.
DI7CT–01
F11490
26A7 R+
7A6 SR
15A7
A714
A6
A6
A6
A7
A7
A7
5
6
11
12
2
1
SRLH
SRLR
SFLH
SFLR
SRRH
SRRR
SFRH
SFRR
W
W–L
BS
W–R
W–B
R–L
R–W
1A
4
R–B
R–G
W–G
GND
GND
A7
A7
12
25W–B
A13
A12
A12
A12
A12
A12
A12
A12
A12
2
6
3
7
8
1
5
SFLH
SFLR
SRRH
SRRR
4
1
5 3
2
ABS SOL Relay
R/B No. 4, J/B No. 4
FL Main
Battery
ALT
IF210
FL Block, J/B No. 1
B–L
IA2
1
1
1
2
ABS Actuator
J2 J/CA
10
11
4
5
IH
ABS ECU
IF1
IF1
IF1
IF1
7
8
9
6
W
W–R
R–B
R–G
L L
IF24
4
4
4
4 4A1
R–B9
1B
L–B
R–L
H1
H1
IF1
IF1
W–L
R–W
W–G
SRLH
SRLR
SFRH
SFRR
A
A
ABS1B–GR
R–B
W–B
2 1
–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEMDI–179
343Author: Date:
2000 MR2 (RM760U)
WIRING DIAGRAM
F10857
LOCK
5 (+)(–)
R/B No. 4
DI–180–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEM
344Author: Date:
2000 MR2 (RM760U)
INSPECTION PROCEDUREHINT:Start the inspection from step 1 in case of using the TOYOTA hand–held tester and start from step 2 in caseof not using the TOYOTA hand–held tester.
1 Check ABS solenoid relay (Marking: ABS SOL) operation.
PREPARATION:(a) Connect the TOYOTA hand–held tester to the DLC3.(b) Turn the ignition switch ON and push the TOYOTA hand–held tester main switch ON.(c) Select the ACTIVE TEST mode on the TOYOTA hand–held tester.CHECK:Check the operation sound of the ABS solenoid relay when operating it with the TOYOTA hand–held tester.OK:
The operation sound of the ABS solenoid relay should be heard.
OK Go to step 5.
NG
2 Check voltage between terminal 5 of R/B No. 4 (for ABS solenoid relay (Marking:ABS SOL)) and body groud.
PREPARATION:Remove the ABS solenoid relay from the R/B No. 4.CHECK:Measure the voltage between terminal 5 of the R/B No. 4 (forABS solenoid relay) and body ground.OK:
Voltage: 10 – 14 V
NG Check and repair harness or connector be-tween R/B No. 4 and battery.
OK
F09759
ABSSolenoidRelay
ABSECU
ABS Actuator
3
44
A12
A13
SFRRSFRH
SRLR SRLH SRRH SRRR
SFLHSFLR
A7 A6
R/B No. 4
–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEMDI–181
345Author: Date:
2000 MR2 (RM760U)
3 Check continuity between terminal 3 of R/B No. 4 (for ABS solenoid relay (Mark-ing: ABS SOL)) and each solenoid terminal of ABS ECU.
CHECK:Check the continuity between terminal 3 of the R/B No. 4 (forABS solenoid relay) and terminal SRLR, SRLH, SRRR, SRRH,SFLR, SRLH, SFRR or SFRH of the ABS ECU.OK:
ContinuityHINT:Resistance of each solenoid coilSRLR, SRRR, SFLR, SFRR: 4.3 ΩSRLH, SRRH, SFLH, SFRH: 8.8 Ω
NG Repair or replace harness or ABS actuator.
OK
F09763
BE1840
F11853
5
Continuity
Open
3
21
2 5
1
3
Continuity
2
1
3
5
DI–182–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEM
346Author: Date:
2000 MR2 (RM760U)
4 Check ABS solenoid relay (Marking: ABS SOL).
PREPARATION:Remove the ABS motor relay from the R/B No. 4.CHECK:Check the continuity between each terminal of ABS solenoidrelay.OK:
Terminals 1 and 2 Continuity (Reference value 100 Ω)
Terminals 3 and 5 Open
CHECK:(a) Apply battery positive voltage between terminals 1 and 2.(b) Check continuity between each terminal of the ABS sole-
noid relay.OK:
Terminals 3 and 5 Continuity
NG Replace ABS solenoid relay.
OK
5 Check for open and short circuit in harness and connector between ABS sole-noid relay (Marking: ABS SOL) and ABS ECU (See page IN–28).
NG Repair or replace harness or connector.
OK
If same code is still output after DTC is deleted, check connections. If connections are normal,ECU may be defective.
F11494
IG Switch
2AM1 IG1
1
ECU–IG
B–R13
ABS ECU
IG1
21
AM1
B
IG1Relay
IE
ALT
B–Y
FL Main
BatteryIH
A
J2J/C
W–B
W–B
12
25
GND
GNDW–B
53
3
B–L
1 112
3
3
3
3A1
A
A
FL BlockA7
A7
A7
1
2
W–B
W–L
R/B No. 3, J/B No.3
1
2
–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEMDI–183
347Author: Date:
2000 MR2 (RM760U)
DTC C1241/41 IG Power Source Circuit
CIRCUIT DESCRIPTIONThis is the power source for the ECU, hence the actuators.
DTC No. DTC Detection Condition Trouble Area
C1241/41
Condition 1. or 2. is detected:
1. Vehicle speed is at 3 km/h (1.9 mph) or more and ECU
terminal IG1 voltage is 9.5 V or less, which continues for
10 sec. or more.
2. When IG1 terminal voltage is less than 9.5 V, there is
open circuit in the motor relay or in the solenoid relay, or
the solenoid circuit malfunction.
Battery
Charging system
Power source circuit
WIRING DIAGRAM
DI7CU–01
Y F10859
ECU–IG
R/B No. 3
DI–184–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEM
348Author: Date:
2000 MR2 (RM760U)
INSPECTION PROCEDURE
1 Check ECU–IG fuse.
PREPARATION:Remove the ECU–IG fuse from the R/B No. 3.CHECK:Check the continuity of the ECU–IG fuse.OK:
Continuity
NG Check for short circuit in all harness and com-ponents connected to ECU–IG fuse (See at-tached wiring diagram).
OK
2 Check battery positive voltage.
OK:Voltage: 10 – 14 V
NG Check and repair charging system (See pageCH–2).
OK
F07151
ON
(+) (–)
IG1 GND
GND
13 25
12A7
F07152 F07216
LOCK
GND
GND
12
A7
25
–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEMDI–185
349Author: Date:
2000 MR2 (RM760U)
3 Check voltage of IG1 power source.
In case of using TOYOTA hand–held tester:PREPARATION:(a) Connect the TOYOTA hand–held tester to the DLC3.(b) Turn the ignition switch ON and push the TOYOTA hand–held tester main switch ON.(c) Select the DATALIST mode on the TOYOTA hand–held tester.CHECK:Check the voltage condition output from the ECU displayed on the TOYOTA hand–held tester.OK:
”Normal” is displayed.In case of not using TOYOTA hand–held tester:PREPARATION:Remove the ABS ECU with the connectors still connected.CHECK:(a) Turn the ignition switch ON.(b) Measure the voltage between terminals A7–13 and
A7–12, 25 of the ABS ECU connector.OK:
Voltage: 10 – 14 V
OK Check and replace ABS ECU.
NG
4 Check continuity between terminals GND (A7–12, 25) of ABS ECU connector andbody ground.
PREPARATION:Disconnect the connector from the ABS ECU.CHECK:Measure the resistance between terminal A7–12, 25 of the ABSECU harness side connector and body ground.OK:
Resistance: 1 Ω or less
NG Repair or replace harness or connector.
OK
Check for open circuit in harness and connector between ABS ECU and ECU–IG fuse (See pageIN–28).
F11496
J/CABS ECU
STP5
R2RightStopLight
R1LeftStopLight
H4HighMountedStop Light
S7Stop Light Switch
Battery
STOP
ALT
IJ1
F
EA
2
2
W–BW–B
G
G
G–W
BA1
1
G–W12
1211
FL Main
A7
FL Block
3 3A
WF
J4 J4
D J3
GB
7
G
ED
G
12 1
2
6
2
6
G–W
W–B
R/B No. 3
DI–186–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEM
350Author: Date:
2000 MR2 (RM760U)
DTC C1249/49 Stop Light Switch Circuit
CIRCUIT DESCRIPTIONDTC No. DTC Detection Condition Trouble Area
C1249/49
ABS ECU terminal IG1 voltage is 9.5 V to 18.5 V and ABS
is not operated, the open circuit of the stop light switch con-
tinues for 0.3 sec. or more.
Stop light switch
Stop light switch circuit
WIRING DIAGRAM
DI7CV–01
F07150
(+) (–)
STP
A7
5
–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEMDI–187
351Author: Date:
2000 MR2 (RM760U)
INSPECTION PROCEDURE
1 Check operation of stop light.
CHECK:Check that stop light lights up when brake pedal is depressed and turns off when brake pedal is released.
NG Repair stop light circuit (See page BE–30).
OK
2 Check voltage between terminal STP (A7–5) of ABS ECU and body ground.
PREPARATION:Remove the ABS ECU with the connectors still connected.CHECK:Measure the voltage between terminal A7–5 of the ABS ECUand body ground when the brake pedal is depressed.OK:
Voltage: 8 – 14 V
OK Check and replace ABS ECU.
NG
3 Check for open circuit in harness and connector between ABS ECU and stoplight switch (See page IN–28).
NG Repair or replace harness or connector.
OK
Proceed to next circuit inspection shown onproblem symptoms table (See page DI–162).
F11492
FL Main
Battery
ABS ECU
GND
AW–B
3A13
10MT
A13
A13
12
25GND
2
1
GND
MT
BM
W–B
W–BJ2J/C
26A7 R+
7A6 SR
1
5 3
2
10L L
4
4
4
4
4 4A1
R–B
1B
L
ABS2
B–GR
R–Y
1A
ALT
B–L
1
1
1
2
A7
A6
A
A
BL BM
W–B
12
A7
W–B
W–B
L–W
IF2
IF29
ABS SOL Relay
2 1
IA2
IH
L–W IF1
R/B No. 4, J/B No. 4
ABS Actuator
FL Block, J/B No. 1
DI–188–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEM
352Author: Date:
2000 MR2 (RM760U)
DTC C1251/51 ABS Pump Motor Lock
CIRCUIT DESCRIPTIONDTC No. DTC Detection Condition Trouble Area
C1251/51 ABS actuator pump motor is not operating normally. ABS pump motor
WIRING DIAGRAM
DI7CW–01
F03291
(–)
(+)
1 2A13
–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEMDI–189
353Author: Date:
2000 MR2 (RM760U)
INSPECTION PROCEDURE
1 Check operation of ABS pump motor.
PREPARATION:Disconnect the ABS actuator connector.CHECK:Connect the positive (+) lead to terminal BM (A13–2) and thenegative (–) lead to terminal GND (A13–1) of the ABS actuatorconnector, and check that the pump motor is operating.OK:
The running sound of the pump motor should beheard.
NG Replace ABS actuator.
OK
Check for open circuit in harness and connector between ABS ECU and ABS motor relay (Mark-ing: ABS SOL), and ABS motor relay and ABS actuator (See page IN–28).
DI–190–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEM
354Author: Date:
2000 MR2 (RM760U)
DTC Always ON ABS ECU Malfunction
CIRCUIT DESCRIPTIONDTC No. DTC Detection Condition Trouble Area
Always ON ABS ECU internal malfunction is detected.
Charging system
ABS warning light circuit
Battery
ABS ECU
INSPECTION PROCEDURE
1 Is DTC output?
Check DTC on page DI–154.
YES Repair circuit indicated by code output.
NO
2 Is normal code displayed?
YES Check and replace ABS ECU.
NO
3 Is ABS warning light go off?
YES Check and replace ABS ECU.
NO
DI7CX–01
–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEMDI–191
355Author: Date:
2000 MR2 (RM760U)
4 Check battery voltage.
CHECK:Check the battery voltage.OK:
Voltage: 10 – 14 V
NG Check and repair charging system.
OK
5 Check ABS warning light.
PREPARATION:(a) Disconnect the connector from the ABS ECU.(b) Connect terminal WA (A7–11) of the wire harness and terminal GND (A7–12, 25) of the ABS ECU con-
nector.(c) Turn the ignition switch ON.CHECK:Check the ABS warning light goes off.
OK Check and replace ABS ECU.
NG
Check for short circuit in harness and con-nector between combination meter and ABSECU (See page IN–28).
F11497
ABS ECU
WA11
R–GC11
ABS
Combination Meter
C10
C11
12
10
GAUGE
IG1 Relay
3 5
1 2
3A1
AM1
1
ALT
FL Main
Battery
W–B
B–L
1 112
W–B
B
AM1
A7
IG Switch
IG1
2 3
3
3
1
2
312
FL Block
IHIE
R–B
1
2
W–L
B–Y
R/B No. 3, J/B No.3
DI–192–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEM
356Author: Date:
2000 MR2 (RM760U)
ABS Warning Light Circuit
CIRCUIT DESCRIPTIONIf the ECU detects trouble, the ABS warning light lights up while at the same time prohibiting ABS control.At this time, the ECU records a DTC in memory.Connect terminals Tc and CG of the DLC3 to make the ABS warning light blink and output the DTC.
WIRING DIAGRAM
DI7CY–01
–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEMDI–193
357Author: Date:
2000 MR2 (RM760U)
INSPECTION PROCEDUREHINT:Troubleshoot in accordance with the chart below for each trouble symptom.
ABS warning light does not light up *1
ABS warning light remains on *2
*1: Start the inspection from step 1 in case of using the TOYOTA hand–held tester and start from step 2 incase of not using TOYOTA hand–held tester.*2: After inspection of step 3, start the inspection from step 4 in case of using the TOYOTA hand–held testerand start from step 5 in case of not using TOYOTA hand–held tester.
1 Check operation of ABS warning light.
PREPARATION:(a) Connect the TOYOTA hand–held tester to the DLC3.(b) Turn the ignition switch ON and push the TOYOTA hand–held tester main switch ON.(c) Select the ACTIVE TEST mode on the TOYOTA hand–held tester.CHECK:Check that the ABS warning light lights up on the combination meter using the TOYOTA hand–held tester.HINT:ABS warning light turns ”OFF” automatically 2 seconds after it is turnd ”ON”.
OK Check and replace ABS ECU.
NG
2 Check ABS warning light.
See combination meter troubleshooting on page BE–2.
NG Repair bulb or combination meter assembly.
OK
3 Check that connectors are securely connected to ABS ECU.
NO Connect connector to ABS ECU.
YES
DI–194–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEM
358Author: Date:
2000 MR2 (RM760U)
Check for open circuit in harness and con-nector between combination meter and ABSECU (See page IN–28).
4 Check operation of the ABS warning light (See step 1).
OK Check and replace ABS ECU.
NG
5 Is DTC output?
Check DTC on page DI–154.
YES Repair circuit indicated by output code.
NO
Check for short circuit in harness and con-nector between DLC3 and ABS ECU (Seepage IN–28).
F11756
J/B No. 6
6E 6H2
IE
ABS ECU
TcP–B
W–BCG
D1DLC3
TcP–B
4
138
A72
F09678
ON(+) (–)DLC3
Tc
CG
–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEMDI–195
359Author: Date:
2000 MR2 (RM760U)
Tc Terminal Circuit
CIRCUIT DESCRIPTIONConnecting between terminals Tc and CG of the DLC3 causes the ABS ECU to display the DTC by flashingthe ABS warning light.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Check voltage between terminals Tc and CG of DLC3.
CHECK:(a) Turn the ignition switch ON.(b) Measure the voltage between terminals Tc and CG of the
DLC3.OK:
Voltage: 10 – 14 V
OK If ABS warning light does not blink even after Tcand CG are connected, ECU may be defective.
NG
DI7CZ–01
DI–196–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEM
360Author: Date:
2000 MR2 (RM760U)
2 Check for open and short circuit in harness and connector between ABS ECUand DLC3, and DLC3 and body ground (See page IN–28).
NG Repair or replace harness or connector.
OK
Check and replace ABS ECU.
F11498
IE
ABS ECU
A7 TsG–R
W–BCG
Ts
4
14
21
D1DLC3
F09679
ON(+) (–)DLC3
Ts
CG
–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEMDI–197
361Author: Date:
2000 MR2 (RM760U)
Ts Terminal Circuit
CIRCUIT DESCRIPTIONThe sensor check circuit detects abnormalities in the speed sensor signal which cannot be detected withthe DTC check.Connecting terminals Ts and CG of the DLC3 starts the check.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Check voltage between terminals Ts and CG of DLC3.
CHECK:(a) Turn the ignition switch ON.(b) Measure the voltage between terminals Ts and CG of the
DLC3.OK:
Voltage: 10 – 14 V
OK If ABS warning light does not blink even after Tsand CG are connected, ECU may be defective.
NG
DI7D0–01
DI–198–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEM
362Author: Date:
2000 MR2 (RM760U)
2 Check for open and short circuit in harness and connector between ABS ECUand DLC3, and DLC3 and body ground (See page IN–28).
NG Repair or replace harness or connector.
OK
Check and replace ABS ECU.
F11757
–DIAGNOSTICS ANTI–LOCK BRAKE SYSTEMDI–199
363Author: Date:
2000 MR2 (RM760U)
Check for Fluid Leakage
Check for fluid leakage from actuator or hydraulic lines.
DI7D1–01
DI7C2–01
Vehicle Brought to Workshop
Customer Problem AnalysisP. DI–201
Check and Clear DTC (Pre–check)P. DI–202
Items inside are titles of pages in this manual,with the page number in the bottom portion. Seethe indicated pages for detailed explanations.
Problem Symptom Confirmation Symptom SimulationP. IN–18
Symptomdoes not occur
Symptomoccurs
DTC CheckP. DI–202
Sensor CheckCircuit Inspection
P. DI–210 to DI–234
DTC ChartP. DI–206
Malfunction code
Problem Symptoms TableP. DI–209
Check for Fluid LeakageP. SR–3
Identification of Problem
Normal code
Repair
Confirmation Test
End
1
2
3 4
5
6 7
89
10
11
Step 2, 5, 8, 9, 11: Diagnostic steps permitting the use of the TOYOTA hand–held tester or TOYOTA break–out–box.
DI–200–DIAGNOSTICS ELECTRO–HYDRAULIC POWER STEERING
364Author: Date:
2000 MR2 (RM760U)
ELECTRO–HYDRAULIC POWER STEERINGHOW TO PROCEED WITH TROUBLESHOOTINGTroubleshooting in accordance with the procedure on the following pages.
DI7C3–01
Inspector’sName :
Customer’s Name
Date VehicleBrought In
Registration Year
Registration No.
Frame No.
Odometer Reading
/ /
/ /
Date Problem First Occurred
Frequency Problem Occurs
/ /
Continuous Intermittent ( times a day)
P/S does not operate.
P/S does not operate efficiently.
P/S Warning LightAbnormal
Remains ON Does not Light Up
DTC Check1st Time
2nd Time
Normal Code Malfunction Code (Code )
Normal Code Malfunction Code (Code )
Symptoms
kmmiles
EHPS Check Sheet
At the time of idling, steering control force is great. (Rest swing is heavy).
Even if the vehicle speed is increased, steering effort does not become greater.
–DIAGNOSTICS ELECTRO–HYDRAULIC POWER STEERINGDI–201
365Author: Date:
2000 MR2 (RM760U)
CUSTOMER PROBLEM ANALYSIS CHECK
F10854
DI7C4–01
A12716DLC3
4 (CG)
13 (Tc)
SST
F10845
F11169 F11170
Normal Code
0.25 sec.
0.25 sec.
2 sec.
ON
OFF
ON
OFF
0.5 sec.
0.5 sec.
Codes 21 and 22
1.5 sec.2.5 sec.
Code 21 Code 22
4 sec.
0.5 sec.
A12801
TOYOTAHand–held Tester
DLC3
DI–202–DIAGNOSTICS ELECTRO–HYDRAULIC POWER STEERING
366Author: Date:
2000 MR2 (RM760U)
PRE–CHECK1. DIAGNOSIS SYSTEM(a) Check the indicator.
When the ignition switch is turned ON, check that the P/Swarning light goes on for 2 seconds.
HINT:If the indicator check result is not normal, proceed to trouble-shooting for the P/S warning light circuit (See page DI–227).
(b) In case of not using TOYOTA hand–held tester:Check the DTC.(1) Using SST, connect terminals Tc and CG of the
DLC3.SST 09843–18040(2) Turn the ignition switch ON.(3) Read the DTC from the P/S warning light on the
combination meter.
HINT: If no code appears, inspect the diagnostic circuit and P/S
warning light circuit (See page DI–227 or DI–230). As an example, the blinking patterns for normal code and
codes 21 and 22 are shown on the left.(4) Codes are explained in the DTC chart on page
DI–206.(5) After completing the check, disconnect terminals Tc
and CG of the DLC3, and turn off the display.If 2 or more malfunctions are indicated at the sametime, the lowest numbered DTC will be displayedfirst.
(c) In case of using TOYOTA hand–held tester:Check the DTC.(1) Hook up the TOYOTA hand–held tester to the
DLC3.(2) Turn the ignition switch ON.(3) Read the DTC by following the prompts on the tes-
ter screen.HINT:Please refer to the TOYOTA hand–held tester operator’s manu-al for further details.
F11791DLC3
OFFON
14 (Ts)
4 (CG)
SST
A12801
TOYOTAHand–held Tester
DLC3
F11789DLC3
14 (Ts)
4 (CG)
SST
–DIAGNOSTICS ELECTRO–HYDRAULIC POWER STEERINGDI–203
367Author: Date:
2000 MR2 (RM760U)
(d) In case of not using TOYOTA hand–held tester:Clear the DTC.(1) Using SST, connect terminals Ts and CG of the
DLC3.SST 09843–18040(2) Turn the ignition switch ON.(3) By making CG terminal ON and OFF 4 times within
8 seconds, delete DTC of the ECU.If making CG terminal ON and OFF within 0.1 se-cond, DTC of will not be deleted.
(4) Check that the warning light shows the normalcode.
(5) Remove the SST from the terminals of the DLC3.SST 09843–18040
(e) In case of using TOYOTA hand–held tester:Clear the DTC.(1) Hook up the TOYOTA hand–held tester to the
DLC3.(2) Turn the ignition switch ON.(3) Operate the TOYOTA hand–held tester to erase the
codes. (See TOYOTA hand–held tester operator’smanual.)
2. INPUT SIGNAL CHECK (TEST MODE)(a) In case of not using TOYOTA hand–held tester:
Check the input signal.(1) Turn the ignition switch OFF.(2) Using SST, connect terminals Ts and CG of the
DLC3.SST 09843–18040(3) Start the engine.(4) Check that the P/S warning light goes on.
HINT:If the P/S warning light does not go on, inspect the P/S warninglight circuit (See page DI–227).
(5) Drive vehicle straight forward at the speed fasterthan 20 km/h (12 mph) for several seconds.
(6) Stop the vehicle.
F11790DLC3
13 (Tc)
14 (Ts)
4 (CG)
SST
F10845 F10847
Malfunction Code (Example Code 72)
7 2
ON
OFF
0.5 sec.0.5 sec.0.5 sec.
1.5 sec. 4 sec.
Repeat0.5 sec.
ON
OFF 0.25 sec.0.25 sec.
Normal Code
A Cycle2 sec.
A12801
TOYOTAHand–held Tester
DLC3
DI–204–DIAGNOSTICS ELECTRO–HYDRAULIC POWER STEERING
368Author: Date:
2000 MR2 (RM760U)
(7) Using SST, connect terminals Tc and CG of theDLC3.
SST 09843–18040(8) Read the number of blinks of the P/S warning light.
HINT: See the list of DTC shown on the bottom of this page. Even a sensor is normal, it outputs code 72 during test
mode. Whether or not the sensor is normal can be judged if the
warning light goes off during driving.
(9) After doing the check, disconnect the SST from ter-minals Ts, Tc and CG of the DLC3, and turn the igni-tion switch OFF.
SST 09843–18040
(b) In case of using TOYOTA hand–held tester:Check the input signal.(1) Hook up the TOYOTA hand–held tester to the
DLC3.(2) Do steps (3) to (6) on the previous page.(3) Read the DTC by following the prompts on the tes-
ter screen.HINT:Please refer to the TOYOTA hand–held tester operator’s manu-al for further details.
–DIAGNOSTICS ELECTRO–HYDRAULIC POWER STEERINGDI–205
369Author: Date:
2000 MR2 (RM760U)
DTC of input signal check function:
Code No.
(See page)Diagnosis Trouble Area
C1572/72
(DI–222)Speed sensor malfunction (Test mode)
Right front, left front, right rear, left rear or speed sensor
Sensor installation
Right front, left front, right rear, left rear or speed sensor rotor
Right front, left front, right rear, left rear or speed sensor cir-
cuit
ABS ECU
Combination meter
Vane pump assembly with motor
DI7C5–01
DI–206–DIAGNOSTICS ELECTRO–HYDRAULIC POWER STEERING
370Author: Date:
2000 MR2 (RM760U)
DIAGNOSTIC TROUBLE CODE CHARTHINT: Using SST 09843–18040, connect terminals Tc and CG of the DLC3. If a malfunction code is displayed during the DTC check, check the circuit listed for the code. For details
of each code, turn to the page referred to under the ”See page” for respective ”DTC No.” in the DTCchart.
DTC No.
(See page)Detection Item Trouble Area
C1521/21
(DI–210)Power Steering Motor Malfunction
Motor temp. sensor (built in vane pump assembly with motor)
Vane pump assembly with motor
C1522/22
(DI–210)Power Steering Motor Malfunction
Motor temp. sensor (built in vane pump assembly with motor)
Vane pump assembly with motor
C1523/23
(DI–210)Power Steering Motor Malfunction
Power steering motor (built in vane pump assembly with mo-
tor)
Vane pump assembly with motor
C1533/33
(DI–214)Power Steering ECU Malfunction
Power steering motor (built in vane pump assembly with mo-
tor)
Vane pump assembly with motor
C1539/39
(DI–214)Power Steering ECU Malfunction Vane pump assembly with motor
C1552/52
(DI–218)PIG Power Source Drop Voltage Malfunction
Open EHPS relay circuit
EHPS relay
Vane pump assembly with motor
C1553/53
(DI–221)When resetting voltage, vehicle is being driven Vane pump assembly with motor
Always ON
(DI–224)Malfunction in ECU
Charging system
Power source circuit
Vane pump assembly with motor
HINT:There is a case that TOYOTA hand–held tester cannot be used when P/S warning light is always on.
DI7C6–01
F10860
Combination Meter(P/S Warning Light)
ECM
EHPS Relay(Marking: EHPS)
DLC3
Vane Pump Assembly with Motor
R/B No. 4
ECU–IG
EHPS Fuse
R/B No. 3
J/B No. 6
FL Block
–DIAGNOSTICS ELECTRO–HYDRAULIC POWER STEERINGDI–207
371Author: Date:
2000 MR2 (RM760U)
PARTS LOCATION
DI7C7–01
H13718
P6 P7 P8
12 1234
5 467
12
38
DI–208–DIAGNOSTICS ELECTRO–HYDRAULIC POWER STEERING
372Author: Date:
2000 MR2 (RM760U)
TERMINALS OF ECU
Symbols (Terminal No.) Wiring Color Condition STD Voltage (V)
MH (P6–1) – PGND (P6–2) W–G ↔ W–B IG switch ON, After 1 sec. or more 10 – 14
IDUP (P7–1) – PGND (P6–2) L–O ↔ W–B Idling 10 – 14
SPD (P7–2) – PGND (P6–2) V–W ↔ W–B IG switch ON, When vehicle speed 12 mph (20 km/h)Pulse generation
(Se page DI–222)
T (P7 3) PGND (P6 2) P B W BIG switch ON, Tc terminal ON Below 1.0
Tc (P7–3) – PGND (P6–2) P–B ↔ W–BIG switch ON, Tc terminal OFF 5
MRLY (P7–5) – PGND (P6–2) W–L ↔ W–B IG switch ON, After 1 sec. or more Below 1.0
EFI (P7–6) – PGND (P6–2) W–G ↔ W–B Idling 5
T (P7 7) PGND (P6 2) G R W BIG switch ON, Ts terminal ON Below 1.0
Ts (P7–7) – PGND (P6–2) G–R ↔ W–BIG switch ON, Ts terminal OFF 5
IGB (P8–1) – PGND (P6–2) B–R ↔ W–B IG switch ON 10 – 14
SIL (P8–2) – PGND (P6–2) W–G ↔ W–B IG switch ON 10 – 14
WL (P8–4) – PGND (P6–2) W ↔ W–BAfter IG switch ON and P/S warning light turns on for 2 sec.,
then it goes offBelow 1.0